Suppose that 9 observations are drawn from a normal population ...

[karen]

Suppose that 9 observations are drawn from a normal population whose standard deviation is 2 . The observations are: 15, 9, 13, 11, 8, 12, 11, 7, and 10 . At 95 confidence, you want to determine whether the mean of the population from which this sample was taken is significantly different from 10.
 a. State the null and alternative hypotheses.
  b. Compute the value of the test statistic.
  c. Compute the p-value.
  d. Interpret the results.

Question 2

Consider the following data set: 14, 14, 15, 16, 18, 19, 19, 20, 21, 22, 23, 25, 25, 25, 25, and 28 . The rank assigned to the four observations of value 25 is:
 a. 12 c. 13
  b. 12.5 d. 13.5

[joanwhite]

Answer to Question 1

a. H0:  = 10 vs. H1:   10
b. z = 1.0
c. 0.1587  2 = 0.3174.
d. Cannot reject H0 . Not enough evidence to say the mean is other than 10.

Answer to Question 2

D

[karen]

Gracias!

[Jossy]

Thanks for the timely response, appreciate it