Question

Find the following critical t-scores used in an 88% confidence interval for a population mean when the population’s standard deviation (σσ) is unknown. Give each answer to at least three decimal places.

• The t-critical value for an 88% confidence interval with sample size 38 is:
• The t-critical value for an 88% confidence interval with sample size 48 is:
• The t-critical value for an 88% confidence interval with sample size 64 is:
• The t-critical value for an 88% confidence interval with sample size 83 is:
• The t-critical value for an 88% confidence interval with sample size 95 is:

In a simple random sample of 95 college graduates who have taken a statistics course, starting salaries had a mean of $58,309. Suppose the distribution of starting salaries among all college graduates who have taken a statistics course is approximately Normal with a standard deviation of $8,672.

1. The margin of error in a 75% confidence interval for the average starting salarly among recent college graduates who have taken a stastics course, based on this sample, is:

   (round to the nearest whole dollar).

2. The 75% confidence interval is:

   <μ<<μ<

   (round each value to the nearest whole dollar)

Answer 1