The lower limit of the confidence interval is then:

x-bar - E = 8.1 - 0.0452 = 8.0548

The upper limit of the confidence interval is then:

x-bar + E = 8.1 + 0.0452 = 8.1452

The confidence interval is then (8.0548, 8.1452)

(If all you want is the final answer, please let me know. It will speed things up if I don't have to type the solution out. Of course, if you're interested in the steps, I'm fine with including it.)

You are given the sample mean and the sample standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Interpret the result and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals.A random sample of 55 home theather systems has a mean price of $143.00 and a standard deviation is $16.80.Construct 90% confidence interval for the poplulation mean.The 90% confidence interval is? (round to two decimal places as needed)

you are given the sample mean and the sample standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Which interval is wider? If convenient, use technology to construct the confidence intervals.

A random sample of 44 gas grills has a mean price of $646.30 and a standard deviation of $57.20.

The 90% confidence interval is? (round to two decimal places as needed)

You are given the sample mean and teh sample sandard deviation.Use this information to construct the 90% and 95% confidence intervals for the population mean. Which interval is wider? If convenient, use the technology to construct the confidence intervals.

A random sample pf 32 eight ounce servings of different juice drinks has a mean of 76.6 calories and a standard deviation of 45.2 calories.

The 90% confidence interval is ? (round to one decimal place as needed)

People were polled on how many books they read the previous year. How many subjects are needed to estimate the number of books read the previous year within one book with 90% confidence? The intial survey results indicate that O (looks kind of like an o symbol) o=13.9 books.

The answer here depends on which value your course uses for a 90% confidence level.

If it uses z = 1.645, then the answer is 523

If, instead, they round it off to z = 1.65, then the answer is 527

We have used 1.645 in previous problems in this set, so hopefully that is the value that they want you to use. This issue didn't come up earlier because it didn't change the value of the answer like it does here.

A doctor wants to estimate the HDLcholestrol of all 20- to 29 year old females. How many subjects are needed to estimate the HDL cholesterol within 2 points with 99% confidence assuming o=13.1? Suppose the doctor would be content with 90% confidence. How does the degrease in confidence affect the sample size required?

Construct the indicated confidence interval for the population mean u using (a) a t-distribution. (b) if you had a incorrectly used a normal distribution, which interval would be wider?

c=0.95, x (with line over it) x=13.3, s=3.0 n=10

(a) the 95% confidence interval using a t distribution is? ( round to one decimal place as needed)

The 95% confidence interval using the t-distribution is (11.2, 15.4).

If you had used the normal distribution the 95% confidence interval would be (11.4, 15.2). The interval using the normal distrubition is narrower than the interval using the t-distribution.

In the following situation, assume the random variable is normally distributed and use a normal distribution or a t-distribution to construct a 90% confidence interval for the population mean. If convenient, use technology to construct the confidence interval.

(a) in a random sample of 10 adults from a near by county, the mean waste generated per person per days was 5.26 pounds and the standard deviation was 1.79 pounds.

(b) Repeat part 9a), assuming the same statistics came from a sample size of 600. Compare the results.

(a) for the sample of 10 adults, the 90% confidence interval is ? 9 round to two decimal places as needed)

Yes, I did. I don't know what happened there. It should have been (5.14, 5.38). I had the numbers in the right places, but something happened when pushing it all through the calculator.

In a survey of 626 males ages 18-64, 391 say they have gone to the dentist in the past year.

Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals.

The 90% confidence interval for the population proportion p is? (round the final answers to the nearest thousandth as needed. Round all intermediate values to the nearest thousandth as needed)

In a survey of 6000 women, 3431 say they change their nail polish once a week. Construct a 99% confidence interval for the population proportion of women who change their nail polish once a week.

A 99% confidence interval for the population proportion is? Round to the nearsest thousandth

A researcher wishes to estimate, with 90% confidence the proportion of adults who have high speed internet access. her estimate must be accurate within 1% of the true proportion.

(a) find the minimum sample size needed, using a prior student that found that 52% of the respondents said they have high speed internet access.

(b) No preliminary estimate is available. Find the minimum sample size needed.

a) what is the minimum sample size needed using a prior study that found that %52 of the respondents said they have highspeed internet access?

n=? round up to the nearest whole number as needed