How JustAnswer Works:

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

Ask Athanassios Your Own Question

Athanassios
Athanassios, Tutor
Category: Homework
Satisfied Customers: 26
Experience:  Academic experience - Math and Computer Science expert
81754
Type Your Homework Question Here...
Athanassios is online now
A new question is answered every 9 seconds

More statistics (Populations and samples used in research)

Customer Question

the daily travel expenses for the sales staff and the audit staff. She collected the following sample
information.

Sales: 131 135 146 165 136 142
Audit: 130 102 129 143 149 120 139

At the .10 significance level, can she conclude that the mean daily expenses are greater
for the sales staff than the audit staff? What is the p-value?

Submitted: 11 years ago.
Category: Homework
Expert:  Athanassios replied 11 years ago.
THIS ANSWER IS LOCKED!

You need to spend $3 to view this post. Add Funds to your account and buy credits.
Expert:  Athanassios replied 11 years ago.
My browser does not display the solution correctly. I don't know if this happens for all browsers. Unfortunately I lack the time to rewrite it, as I must be going to work. I hope you can figure the solution out.
 

Athanassios
Expert:  Athanassios replied 11 years ago.
Hi

 

We have two samples. The mean of the first sample is (131+135+146+165+136+142 ) / 6 = 142.5 

The standard deviation is s1=sqrt((131-142.5)^2 + (135-142.5)^2 + (146-142.5)^2 + (165-142.5)^2 + (136-142.5)^2 + (142-142.5)^2) / (6-1)) = 12.24


Similarly, the mean of the second sample is 130.29 with a standard deviation of 15.79

The test statistic is Z = X1-X2/s


where X1 s the sample mean value for the first sample


X2 is the sample mean value for the second sample

s is the standard deviation of (X1-X2)


s = squareroot(s1^2/n1 + s2^2/n2) =


= sqrt(12.24^2/6+ 15.79^2/7) =


= 7.78


We conduct a right-tailed test , since we only want to check if the mean value of the first population is greater than that of the second population.


At the 0.1 significance level, the critical value is 1.28


Z = X1-X2/s = (142.5-130.29) / 7.78 = 1.569


Since Z = 1.569 exceeds 1.28, we can conclude that the first sample has a greater mean


 

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
< Previous | Next >
  • 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!!!! Alex Los 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. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, 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. Esther Woodstock, 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. Robin Elkton, 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. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • LogicPro

    LogicPro

    Engineer

    Satisfied Customers:

    4925
    Expert in Java C++ C C# VB Javascript Design SQL HTML
< Last | Next >
  • http://ww2.justanswer.com/uploads/ComputersGuru/2010-02-13_051118_Photo41.JPG LogicPro's Avatar

    LogicPro

    Engineer

    Satisfied Customers:

    4925
    Expert in Java C++ C C# VB Javascript Design SQL HTML
  • http://ww2.justanswer.com/uploads/BU/BusinessTutor/2012-2-2_115741_Kouki2.64x64.jpg Manal Elkhoshkhany's Avatar

    Manal Elkhoshkhany

    Tutor

    Satisfied Customers:

    4538
    More than 5000 online tutoring sessions.
  • http://ww2.justanswer.com/uploads/LI/lindaus/2012-6-10_04811_IMG20120609164157.64x64.jpg Linda_us's Avatar

    Linda_us

    Finance, Accounts & Homework Tutor

    Satisfied Customers:

    3138
    Post Graduate Diploma in Management (MBA)
  • http://ww2.justanswer.com/uploads/chooser77/2009-08-18_162025_Chris.jpg Chris M.'s Avatar

    Chris M.

    M.S.W. Social Work

    Satisfied Customers:

    2602
    Master's Degree, strong math and writing skills, experience in one-on-one tutoring (college English)
  • http://ww2.justanswer.com/uploads/JawaadAhmed/2009-6-27_12137_SIs_SHadi.jpg F. Naz's Avatar

    F. Naz

    Chartered Accountant

    Satisfied Customers:

    2126
    Experience with chartered accountancy
  • http://ww2.justanswer.com/uploads/JK/jkcpa/2011-1-16_182614_jkcpa.64x64.jpg Bizhelp's Avatar

    Bizhelp

    CPA

    Satisfied Customers:

    1887
    Bachelors Degree and CPA with Accounting work experience
  • http://ww2.justanswer.com/uploads/avremote/photoa.jpg Seanna's Avatar

    Seanna

    Tutor

    Satisfied Customers:

    1781
    3,000+ satisfied customers, all topics, A+ work
 
 
 

Related Homework Questions