Question

An article in the San Jose Mercury News stated that students in the California state university system take 4.5 years, on average, to finish their undergraduate degrees. Suppose you believe that the mean time is longer. You conduct a survey of 49 students and obtain a sample mean of 5.1 with a sample standard deviation of 1.2. Do the data support your claim at the 99% confidence level?

Answer 1

This is the two tailed test .

The null and alternative hypothesis is

H₀ : = 4.5

H_a : > 4.5

Test statistic = t

= ( - ) / s / n

= (5.1 - 4.5) / 1.2 / 49

= 3.5

Test statistic = 3.5

df = 48

P-value = 0.0005

= 0.01

P-value <

Reject the null hypothesis .

Data support your claim at the 99% confidence level .