Question

From a random sample of

66

students in an introductory finance class that uses​ group-learning techniques, the mean examination score was found to be

79.84

and the sample standard deviation was

2.5

For an independent random sample of

88

students in another introductory finance class that does not use​ group-learning techniques, the sample mean and standard deviation of exam scores were

73.38

and

8.5

respectively. Estimate with

95​%

confidence the difference between the two population mean​ scores; do not assume equal population variances.

The

95​%

confidence interval is from a lower limit of

nothing

to an upper limit of

nothing .

​(Round to two decimal places as​ needed.)

Answer 1

Solution: The 95% confidence interval is:

To find the t value, we need to find the degrees of freedom.

Therefore, the 95% confidence interval is from a lower limit of 4.56 to an upper limit of 8.36