Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

iPad 10:54 AM 5. You take a sample of 16 from a population of test scores with p

ID: 3074404 • Letter: I

Question

iPad 10:54 AM 5. You take a sample of 16 from a population of test scores with population standard deviation 10, and the mean of your sample is 60. If you want to find the 99% confidence interval on the population mean, (a) You need first to find the critical value from--.(1 point) a. t table b. z table (b) What is the critical value you need to find? Round your answer to two decimal places. (I point) (c) What is the 99% confidence interval on the mean? Round your answer to two decimal places. (2 points) 6. Based on question 5, now assume that you do not know the population standard deviation, but the standard deviation in your sample is 10. If you want to find the 95% confidence interval on the population mean, (a) You need first to find the critical value from (1 point) a. t table b. z table (b) What is the critical value you need to find? Round your answer to two decimal places. (1 point) (c)what is the 95% confidence interval on the mean now? (2 points) (d) Assume the population mean in this question is u. Based on the confidence interval you calculated in (c), what would be the conclusion of a one-sample t test with alpha 0.05 of Ho: - 70 vs. H: H70? (I point) a. reject the null hypothesis b. fail to reject the null hypothesis

Explanation / Answer

Ans:

5

a)z table,as population standard deviation is known

b)z critical value=2.58

c)99% confidence interval for population mean

=60+/-2.58*(10/sqrt(16))

=60+/-6.45

=(53.55, 66.45)

6)

a)t table,as population standard deviation is unknown.

b)df=16-1=15

critical t value=tinv(0.05,15)=2.13

c)95% confidence interval for population mean

=60+/-2.13*(10/sqrt(16))

=60+/-5.325

=(54.675, 65.325)

d)As,above CI does not include 70 within its limits,so reject the null hypothesis.