For a normal distribution, a positive value of z indicates that ...

[james]

For a normal distribution, a positive value of z indicates that
 a. all the observations must have had positive values.
   b. the area corresponding to the z is either positive or negative.
   c. the sample mean is smaller than the population mean.
   d. the sample mean is larger than the population mean.

Question 2

Student advisors are interested in determining if the variances of the scores of day students and night students are the same. The following samples are drawn: Day Night n1 = 25 n2 = 31 s1 = 9.8 s2 = 14.7 Test the equality of the variances of the populations. Let  = .05.

[akpaschal]

Answer to Question 1

d

Answer to Question 2

Since F = 2.25 > 2.21 (p-value is between .02 and .05), reject H0.