In order to estimate the average time spent per student on the ...

[krzymel]

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.8 hours. If the sample mean is 9 hours, then the 95 confidence interval is
 a. 7.04 to 10.96 hours.
   b. 7.36 to 10.64 hours.
   c. 7.80 to 10.20 hours.
   d. 8.61 to 9.39 hours.

Question 2

In a sample of 400 people, 250 indicated that they prefer domestic wines, while 140 said they prefer European wines, and 10 indicated no preference. 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 wine. Hint: Use the continuity correction factor.
 a. Provide the hypotheses to be tested.
  b. Compute the mean.
  c. Compute the standard deviation.
  d.. At  = .05, test to determine if there is evidence of a significant difference in the preferences for the two types of wine.

[ktidd]

Answer to Question 1

d

Answer to Question 2

a. H0: p = .5
Ha: p  .5
b. 195
c. 9.874
d.. Test Statistic z = 5.52; p-value < .05, therefore reject H0 and conclude that there is a significant difference in the preferences for the two types of wine.

[krzymel]

Excellent

[Bigfoot1984]

Gracias!