Question

In a sample of n=3,600 students, the average GPA was x⎯⎯=3.5 with a sample variance of s2=0.25. Calculate the 98% confidence interval for the population GPA μHolding everything constant, what would be the lower limit of the 90% confidence interval for the population mean? (round to two digits)

Question 7 options:

	3.48
	3.49
	3.51
	3.52

Answer 1

Solution :

Given that,

t ,df = 1.228

Margin of error = E = t,df * (s /n)

= 1.228 * (0.5 / 3600)

Margin of error = E = 0.01

The 90% lower confidence interval estimate of the population mean is,

- E < < + E

3.5 - 0.01

3.49

Lower limit: 3.49

answered by: anonymous