Math Homework

Ask Math Questions. Get Help With Your Math Homework

Get an Answer ASAP!

Math Homework
This answer was rated:

# need help with a math project due today at midnight... its

about life expectancy and interpreting...
need help with a math project due today at midnight... its about life expectancy and interpreting models of linear equations and graphs and answering a couple of questions along with complete show of work.... anyone up for helping me?
Show More
Show Less
Answered in 4 minutes by:
10/21/2013
Ray Atkinson, Bachelor's Degree
Category: Math Homework
Satisfied Customers: 1,890
Experience: Inner-city high school substitute teacher. Degrees in mathemetics, accounting, and education. Years and years of tutoring.
Verified

Ray Atkinson :

Please give details and I will see if I can help.

Customer:

MAT 171 Project I Life Expectancy Fall 2013

Over the last one hundred years, the average life expectancy of both men and women has increased significantly. In this project, you will investigate the trends concerning average life expectancy and use linear modeling to answer questions about these trends.

The purpose of this project is for you to apply concepts we have discussed in class, such as modeling with the TI-83/84 calculator, drawing scatter plots, making predictions, and solving systems of linear equations. Follow the directions for each part. When answering a question you must answer in complete sentences. You may work with a friend, but each person must turn in their own project.

Part I. Visualizing the data

You will need to draw a scatter plot according to the directions below. Use a whole sheet of graph paper. The table below shows the life expectancy at birth, by gender, for the years indicated, beginning in 1900 and continuing through 2000.

Year Life expectancy of males Life expectancy of females

1900 47.9 1910 49.9 1920 55.5 1930 57.5 1940 61.6 1950 65.5 1960 66.8 1970 67.0 1980 70.1 1990 71.8 2000 74.1

Follow the directions carefully.

50.7 53.2 57.4 60.9 65.9 71.0 73.2 74.6 77.6 78.8 79.5

1. Use the horizontal x-axis to represent the year. Label the axis counting by 10s, starting with 1840 and continue through 2020. The origin is still the origin. Indicate on the axis that you are skipping many years

2. Use the vertical y-axis to represent life expectancy. Label the axis counting by 5s. (This means the numbers can increase by 5, this does not mean each horizontal line is an increment of 5. You could use two lines.)

3. Use a plus “+ “ sign to represent the data for men, and plot the points on the graph paper using the year as the x coordinate and the life expectancy of men as the y coordinate. On the same graph, use an “o” to represent the data for women, and plot the points on the graph using the year as the x coordinate and the life expectancy of women as the y coordinate.

Part II. Finding the Linear Models

1. Using the years as x and the life expectancy of males as y, enter the data in your calculator in L1 and L2, respectively. Enter the life expectancy of females as a third list in L3.

2. Set up the Plots options:  Pressing 2nd Y= puts you in the STAT PLOTS menu. Turn on Plot1

and make sure that the Xlist is L1 and the Ylist is L2. Change the

Mark: to the „+‟ (at the bottom of the screen).  You can access the Plot2 menu from the screen you are currently at

by going to the top of the screen and highlight Plot2 then press ENTER. Turn on Plot 2. Change the Ylist to L3. Move the cursor just to the right of the Ylist:. Press 2nd 3 and you should get L3. Make sure the Mark: is the □.

 Use Zoom 9 to view the scatter plot after you have set up the plots.  Change the WINDOW options to match the parameters of your

hand-drawn graph. Now, the calculator‟s graph should resemble the one you drew in part I.

3. Using the CALC option under STATS menu, use LinReg to find a linear model (equation) for L1 and L2. This is the equation predicting the life expectancy for males. Record this equation. Round off the values for a and b to two decimal places.

4. Now find the linear equation predicting the life expectancy for females. This time you need to use L1 and L3 when calculating LinReg. Record this equation. Again, round off the values for a and b to two decimal places.

5. Draw the lines representing the equations you found for the Life Expectancy of Males and the line for Life Expectancy of Females on the graph you created in Part I. To do this -- to pick two values for x that are a multiple of 10 between 1840 and 2000. Then solve for y for each. You will now have two points to help you draw a line. [Write out all the calculations] Do the lines appear to intersect? Where? Give approximate coordinates, based on your graph, as integers. Mark the point on your graph. [These questions need to be answered in complete sentences.]

III. Interpreting the Models

For this section, you need to respond in complete sentences. Make sure you answer the questions thoughtfully and completely. If you are asked to calculate anything, you MUST show ALL of the necessary steps.

1. AccordingtothelinearmodelsyoufoundinPartII,wasthereinthepastor will there be in the future a year in which the life expectancy of males and the life expectancy of females was or will be the same? To answer this question, you must find the point of intersection for your two equations.

You will be solving a system of simultaneous equation. How does your answer compare to the point you found in Part II, #5 above?

2. Useyourmodelstopredictthelifeexpectancyofmalesandfemalesbornin 2015 and in 2025.

3. What do your linear models suggest the life expectancy of males and females to have been in 1850? According to an official source [the writer of this assignment –not me- did not provide this important piece of information], the estimated life expectancy of males born in 1850 was 38 and the estimated life expectancy of females born in 1850 was 40. How do your values compare to these numbers?

4. What are the values for the y-intercepts for both linear models? (Show the work)

Interpret the meaning of these y-intercepts.

5. Analyze the linear models you found in this assignment. Do you think these linear models are valid? Do they accurately describe how long an average male or female lived in the past or will live? Why? Are these models useful? When would one need to use a prediction of life expectancy? This part must be answered in the form of a short essay (at least 1⁄2 a page). State your position and provide arguments supporting your position. You may use mathematically based arguments or other knowledge (facts, not opinions) to make your arguments.

Customer:

I need help on the question number 5 on part 2 and all of the questions on part 3... not that much i think... I needed for tonight at midnight... you think you can do it? i need all work shown as well thanks...

Customer:

hey you think you can help me?

Ray Atkinson :

Correct me if I am wrong. You just need the linear regression equation and evaluate them at 1850, 2015, and 2025?

Customer:

idk i just need the answers for the question 5 from part 2 and the rest of the answers for the questions on part 3 from 1-5

Ray Atkinson :

Are the values given next to the years the males and a line below that the females?

Customer:

yes

Customer:

how do you attache documents in here

Ray Atkinson :

Ok, last question. what time is it where you are?

Customer:

so i can attache the project

Customer:

the time is 9:44

Ray Atkinson :

Excellent. 2:16 to go.

Customer:

yes

Customer:

u think u can help me in the 2:16?

Ray Atkinson :

If you do not have a paper clip icon above where you type, you can use sendspace.com to upload the file and give me the link for the download

Ray Atkinson :

unless I have technical problems, I can get it done in plenty of time.

Customer:

how do i send it to you on there?

Ray Atkinson :

If you upload the file there, there is a button that says "copy link." Click that, come back here, and paste.

Customer:

http://www.sendspace.com/file/z7mr8k

Customer:

i attached the project... i have already done the 1 part of the project... and part 2 except for question number 5 and i also need part 3 ...

Customer:

where you able to get the project to work correctly?

Ray Atkinson :

I am working on the regression right now.

Customer:

can you show the work?

Customer:

and answer the questions in the order they go thanks

Customer:

???

Ray Atkinson :

working on it right now.

Customer:

thanks

Customer:

when you get questions done could you send some to me so i can copy them down to a piece of paper or are you gonna send them all at once?

Ray Atkinson :

Question for you. Can I do the work in Excel, or does it have to be done by hand?

Customer:

it has to be done by hand... the work has to be shown on paper step by step... its only for the 6 questions

Ray Atkinson :

Ok got it.

Customer:

i can graph the graph required on question 5 if i have the answers

Customer:

question... are you doing all of it or just the ones i asked?

Ray Atkinson :

Sweet. I can use a calculator to get the lines. Let me get them so you can get the graphs done.

Customer:

yeah thanks

Ray Atkinson :

So you need 2.4, 2.5, and all of 3

Ray Atkinson :

!! The instructions say to use a calculator !!

Customer:

to be sure 2.3 2.4 2.5 and all of 3

Customer:

yup i know

Ray Atkinson :

did your instructor tell you different rules?

Customer:

calculator is fine but the other questions say (show wall of work and calculations)

Customer:

so please just show the work and answer the questions like the project asks... in full sentences and with all calculations and all work... thank you very much! :) i appreciate it

Ray Atkinson :

You can get started on this
Equation for males is y=0.26x-445.55
Equation for females is y=0.31x-538.21

Ray Atkinson :

that is actually the answers for 2.3 and 2.4

Customer:

got those thanks

Customer:

i will wait on the rest

Customer:

:)

Ray Atkinson :

Using 1900 and 2000 as the points to draw the regression lines:
0.26(1900)-445.55 = 494-445.55 = 48.45, so (1900, 48.45)
0.26(2000)-445.55 = 520-445.55 = 74.45, so (2000, 74.45)

0.31(1900)-538.21 = 589 - 538.21 = 52.79, so (1900, 52.79)
0.31(2000)-538.21 = 620 - 538.21 = 81.79, so (2000, 81.79)

Ray Atkinson :

That is 2.5

Customer:

whats 2.5 for?

Customer:

got it thanks

Ray Atkinson :

(any two lines with different slopes are going to cross)
It looks like they cross about the year 1850 with a value around 35 years

Ray Atkinson :

Write this:
The lines definitely cross, since they have different slopes. They cross near the year 1850 at a life expectancy of about 35 years.

Ray Atkinson :

Ok, now for part 3 and the calculations.

Ray Atkinson :

y=0.26x-445.55
y=0.31x-538.21

Subtract line 2 from line 1

0 = 0.05x-92.66
92.66 = 0.05x
x=1853.2

0.26(1853.2)-445.55 = 481.832-445.55 = 36.282

the intersection is (1853.2, 36.282)

Ray Atkinson :

those are quite close to my estimate from the graph

Customer:

alright thanks.. im copying them down and checking them as they go ... if i have question i will ask them as i get done copying each one thanks

Ray Atkinson :

Males at 2015 are 0.26(2015)-445.55 = 523.9 - 445.55 = 78.35
Males at 2025 are 0.26(2025)-445.55 = 526.5 - 445.55 = 80.95

Ray Atkinson :

Females at 2015 are 0.31(2015)-538.21 = 624.65 - 538.21 = 86.44
Females at 2025 are 0.31(2025)-538.21 = 627.75 - 538.21 = 89.54

Ray Atkinson :

Males at 1850 were 0.26(1850)-445.55 = 481-445.55 = 35.45
Females at 1850 were 0.31(1850)-538.21 = 573.5-538.21 = 35.29

Ray Atkinson :

The regression lines calculated return estimates for the year 1850 that are slightly under the given facts. Since the difference is less than 5 years, I would still call that reasonably accurate.

Customer:

okay im getting confused... im just now starting on part 3 which answer belong to which question?

Ray Atkinson :

The y-intercept would be the life expectancy for the year 0. Since the estimates would be -445.55 years of age and -538.21, the regression line is meaningless towards that point.

Ray Atkinson :

From the 2 equations and the simultaneous equations to my "quite close" statement is 3.1

Ray Atkinson :

The calculation for 2015 and 2025 are 3.2

Ray Atkinson :

The numbers for 1850 are 3.3

Ray Atkinson :

My comment about year 0 is 3.4

Ray Atkinson :

Now, I need to do some writing for 3.5

Customer:

okay im copying down all of this information ... thanks ... good so far

Ray Atkinson :

I am normally a very concise writer, so I am trying to pad the text out without looking fake. You may (very likely) want to reword what I am writing to be more your style.

Ray Atkinson :

I am a math/accounting major. Not English.

Ray Atkinson :

The linear models are valid, within a limited window of time. Solving for y=0, both equations hit y=0 in the early 1700s, apparently saying that no one lived at all before then. Since this is nonsense, the life expectancy regression line for longer periods must either not be linear, or else the slopes must be shallower. The lines are probably reasonably accurate for the time periods covered. The values for 1850 were close (within 15% off the real values) and modern numbers are done carefully. As for predictions for the future, there is no validity. There could be a medical breakthrough tomorrow that doubles the life expectancy. As for the models usefulness, they do show some interesting information. They definitely show that people are living longer as time goes by. Men’s expectancy goes up 2.6 years every 10, and women’s goes up by 3.1 years every 10. This leads to speculation as to why. Is it nutrition, medicine, crime, environment, evolution? Questions are the beginning of the scientific method, and studies are done all the time in an attempt to explain the facts. Besides all that, life expectancy tables are used every day by life insurance companies as a guess as to how long someone will life to make payments before the company has to pay back.

Customer:

okay sounds good to me

Ray Atkinson :

217 words is almost a half page. The prof should be happy with that

Customer:

yeah i think that is enough... thanks .. all is good...

Ray Atkinson :

If you want to pad that out more, be my guest.

Ray Atkinson :

and fix the typo in the last sentence.

Ray Atkinson :

life -> live

Customer:

yeah thanx

Ray Atkinson :

If there is anything you need clarified, please ask. Please do remember to rate my answer when you are satisfied. If I have given excellent service, consider giving a tip.

Customer:

yes thanks... im still copying everything down.. and yes i will rate your question... thanks for all i appreciate it.

Ray Atkinson :

You are more than welcome. If you need me in the future, you can ask for me by name in the question.

Ray Atkinson, Bachelor's Degree
Category: Math Homework
Satisfied Customers: 1,890
Experience: Inner-city high school substitute teacher. Degrees in mathemetics, accounting, and education. Years and years of tutoring.
Verified
Ray Atkinson and 87 other Math Homework Specialists are ready to help you
Ray Atkinson, Bachelor's Degree
Category: Math Homework
Satisfied Customers: 1,890
1,890 Satisfied Customers
Experience: Inner-city high school substitute teacher. Degrees in mathemetics, accounting, and education. Years and years of tutoring.

Ray Atkinson is online now

A new question is answered every 9 seconds

• Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
• Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
• 100% Satisfaction GuaranteeRate the answer you receive.

## JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

## What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

## Meet the Experts:

Mr. Gregory White

Master's Degree

92 satisfied customers

M.A., M.S. Education / Educational Administration

JACUSTOMER-yrynbdjl-

Master's Degree

49 satisfied customers

I have taught college Mathematics for the past 10 years.

SusanAthena

Master's Degree

41 satisfied customers

Tutor for Algebra, Geometry, Statistics. Explaining math in plain English.

Dr Arthur Rubin

Doctoral Degree

37 satisfied customers

Ph.D. in Mathematics, California Institute of Technology

mhasan420

Master's Degree

29 satisfied customers

BA Maths, Oxford

Don

Master's Degree

17 satisfied customers

M.S. Astronautical Engineering. Math/Science/Comp Tutor

Eric M.

Associate Degree

15 satisfied customers

BS and MS in computing with background in advanced statistics, combinatorics, linear algebra, calculus, and advanced algorithms.

< Previous | Next >

Related Math Homework Questions
I have searched and cannot find a similar question to this
Hi, I have searched and cannot find a similar question to this that has been answered...Q. With a fair coin, my opponent flips 50 times, & I call heads or tails. It is fair odds, ie I get back 2xbet i… read more
GLENN
Master of Mathematics
329 satisfied customers
The life spans of three randomly selected tires are 33 comma
The life spans of three randomly selected tires are 33 comma 40033,400 ​miles, 42 comma 60042,600 ​miles, and 38 comma 00038,000 miles. Using the empirical​ rule, find the percentile that corresponds … read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
FOR. mate, from the lens proof we discussed last week, could
FOR RYAN. Hi mate, from the lens proof we discussed last week, could you provide me a new copy with the "t" values changed to a "w" (for width) and the "w" values changed to a "l" (length). That is mo… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
How quickly can a question be answered? This question is in
This question is in regards ***** *****'s theorem and the empirical rule. … read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
Customers arrive at a movie theater at the advertised movie
Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and prepreview ads before the movie starts. Many complain that the time dev… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
I am designing a paddle wheel for a project. The diameter of
I am designing a paddle wheel for a project. The diameter of the paddle is fixed. I'm looking for analystical calculation to determine the width I need to move mass I have through the water. The axis … read more
Matt
Engineer
Bachelor\u0027s Degree
5 satisfied customers
I really appreciated your assistance the last time and I
Hi Ryan,I really appreciated your assistance the last time and I have something else I need assistance with if you are interested relating to statistics.… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
FOR., could we please touch base about a question earlier
FOR RYAN. Hi Ryan, could we please touch base about a question earlier this year - regarding the proof for an area of a lens… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
U.S. debt For selected years from 1900 to 2014, the national
U.S. debt For selected years from 1900 to 2014, the national debt d, in billions of dollars, can be modeled by d = 1.60e0.083t where t is the number of years past 1900. (Source: Bureau of Public Debt,… read more
mathwhiz123
37 satisfied customers
A new sidewalk will be 4 feet​ wide, 120 feet​, and filled
A new sidewalk will be 4 feet​ wide, 120 feet​ long, and filled to a depth of 9 inches ​(0.75 ​foot) with concrete. How many cubic yards of concrete are​ needed? … read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
The next number in the series 38, 36, 30, 28, 22, is:
The next number in the series 38, 36, 30, 28, 22, is: The next number in the series 1, 3, 9, 27, 81, is: The next number in the series 9, 4, 10, 5, 11, 6, is: You want to get an oil change every 4,000… read more
SusanAthena
Master's Degree
Master's Degree
41 satisfied customers
What I have are buckets of response times (10ms, 25ms, 50ms,
what I have are buckets of response times (10ms, 25ms, 50ms, etc) and for each request, it will increment the bucket counter by 1 that it falls in. For example, if a request took 30ms, the 50ms bucket… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
The radius of the earth is 6400 km — a satellite is in a
the radius of the earth is 6400 km — a satellite is in a circular orbit at an altitude of 600 km above earth. find the speed of the satellite and the acceleration.… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
Attached are some questions that I need your help with. I
Hi Ryan, Attached are some questions that I need your help with. I need these done with the explanation as well and also you can't use excel solver for these. If the python questions present a problem… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
This isn't a homework question. A friend posed a message on
Hi, this isn't a homework question. A friend posed a message on FB about the bar exam pass rate. In doing so a friend of his provided math in order to qualify the 36%. His math does not make sense to … read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
Im stuck on factoring... I actually can't wrap my mind
Im stuck on factoring... I actually can't wrap my mind around it. The question is 49m^2-16 … read more
Sandhya_sharma
Master\u0027s Degree
559 satisfied customers
You plan to take out a​ 30-year fixed rate mortgage for
You plan to take out a​ 30-year fixed rate mortgage for ​\$275,000. Let​ P(r) be your monthly payment if the interest rate is​ r% per​ year, compounded monthly. Interpret the equations ​(a) ​P(3​)=1159… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
Can you help me with homework question. How I can send the
can you help me with homework question JA: The Math Tutor can help you get an A on your homework or ace your next test. Tell me more about what you need help with so we can help you best. Customer: ho… read more
Ryan
Bachelor\u0027s Degree
1,060 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less