You decide to conduct a survey of a sample of 25 members of this year's graduating class and find that the average GPA is 3. The standard deviation...

You decide to conduct a survey of a sample of 25 members of this year’s graduating class and find that the average GPA is 3.2. The standard deviation of the sample is 0.4. Over the last ten years, the average GPA has been 3.0. Is this year’s class significantly different from the long-run average? At what alpha level would it be significant?

The null hypothesis is H0:µ=3The alternative hypothesis is H1:µ≠3The test statistic is: Z=(xbar-µ)/(sigma/sqrt(n))Here ,. Xbar =3.2µ=3sigma=0.4n=25, which gives, Z=2.5The null...