Question

Question Completion Status: QUESTION TZ A sample of size 18 is drawn from a population with standard deviation 2.3. Calculate the standard error of the mean. Round your answer to 2 decimal points if needed. QUESTION 13 Suppose ACME corporation is trying to test if their new propane gas tank lasts longer than the 20 hours their previous model lasted. Which one of the following is a correctly stated hypothesis? A HT: 220 OB, Ho: 220 c. Ho: u > 20 OD, H4>20 QUESTION 14 We would like to construct a 90% confidence interval for the mean, based on a sample of 35 observations. The sample standard deviation is 3 and the sample mean is 15. Calculate the upper confidence limit. Round your answer to 3 decimals if needed. QUESTION 15 When calculating the critical values that are used to construct confidence intervals for the difference in means between 2 populations, we always need to split the significance level in two. True False

Answer 1

Solution:

Question 12:

Standard error = $\frac{\sigma}{\sqrt{n}}=\frac{2.3}{ \sqrt{18}}=0.5424=0.54$

Standard error = 0.54

Questio 13:

Option (d) is correct.

$H_{1}:\mu>20$

Question 14:

Upper control limit $=\bar{X}+Z_{_{\alpha /2}}\frac{\sigma}{\sqrt{n}}$

Upper control limit $=15+1.645\frac{3}{\sqrt{35}}=15.834$

Upper control limit = 15.834

Question 15:

Statement is TRUE

It is correct.

Thank you....!!