The monthly sales records of two branches of a department store ...

[HudsonKB16]

The monthly sales records of two branches of a department store (Branch A and Branch B) over the last year (12 months) were gathered. It was decided to use the Mann-Whitney-Wilcoxon test to determine if there has been a significant difference between the sales of the two branches.
 a. Provide the hypotheses for this test.
  b. Compute the mean T.
  c. Compute the standard deviation T.
  d. The sum of the ranks for branch A was determined to be 184.5 . Compute the test statistic Z.
  e. Use  = 0.05 and test to determine if there is a significant difference in the populations of the sales of the two branches.

Question 2

In a sample of 200 racquetball players, 120 indicated they prefer Penn racquetballs, 75 favored Ektelon, and 5 were indifferent. We want to use the sign test to determine if there is evidence of a significant difference in the preferences for the two types of racquetballs.
 a. Provide the hypotheses to be tested.
  b. Compute the mean.
  c. Compute the standard deviation.
  d.. At 95 confidence, test to determine if there is evidence of a significant difference in the preferences for the two types of racquetballs.

[brittiany.barnes]

Answer to Question 1

a. Ho: The two populations are identical.
Ha: The two populations are not identical.
b. 150
c. 17.32
d. 1.99
e. p-value <  = 0.05, the null hypothesis is rejected (actual p-value using Excel =0.046).

Answer to Question 2

a. Ho: P = 0.5
Ha: P  0.5
b. 97.5
c. 6.982
d.. Test Statistic Z = 3.22; p-value < 0.05, therefore reject Ho (p-value, using Excel = 0.00127)