6.Assuming the same level of significance a , as the sample size increases, the
ID: 3355836 • Letter: 6
Question
6.Assuming the same level of significance a, as the sample size increases, the value of ta/2 becomes larger and larger than the value of za/2. true/false
8.When the population is normally distributed and the population standard deviation s is unknown, then for any sample size n, the sampling distribution of is based on the t distribution. true/false
10. When the level of confidence and the sample size remain the same, a confidence interval for a population mean µ will be narrower, when the sample standard deviation s is larger than when s is smaller. true/false
12. The manager of the quality department for a tire manufacturing company wants to know the average tensile strength of rubber used in making a certain brand of radial tire. She knows the population standard deviation and uses a Z test to test the null hypothesis that the mean tensile strength is 800 pounds per square inch. The calculated Z test statistic is a positive value that leads to a p-value of .067 for the test. If the significance level is .01, the null hypothesis would be rejected. Assume that the population of pressure values is normally distributed. true/false
Explanation / Answer
6) False
Correct statement: the same level of significance a, as the sample size increases, the value of ta/2 gets closer to the value of za/2
8) True
When the population is normally distributed and the population standard deviation s is unknown, then for any sample size n, the sampling distribution of is based on the t distribution.
10) False
Correct statement: when the level of confidence and the sample size remain the same, a confidence interval for a population mean µ will be wider, when the sample standard deviation s is larger than when s is smaller.
12) False
Correct statement:
The manager of the quality department for a tire manufacturing company wants to know the average tensile strength of rubber used in making a certain brand of radial tire. She knows the population standard deviation and uses a Z test to test the null hypothesis that the mean tensile strength is 800 pounds per square inch. The calculated Z test statistic is a positive value that leads to a p-value of .067 for the test. If the significance level is .01, the null hypothesis would not be rejected. Assume that the population of pressure values is normally distributed.