Sony would like to test the hypothesis that the average age of a ...

[DyllonKazuo]

Sony would like to test the hypothesis that the average age of a PlayStation user is different from the average age of an Xbox user.
 
  A random sample of 36 PlayStation users had an average age of 34.2 years while a random sample of 30 Xbox users had an average age of 32.7 years. Assume that the population standard deviation for the age of PlayStation and Xbox users is 3.9 and 4.0 years, respectively. Sony would like to set  = 0.10. Which one of the following statements is true?
  A) Because the 90 confidence interval includes zero, we fail to reject the null hypothesis and cannot conclude that the average age of PlayStation users is different from the average age of Xbox users.
  B) Because the 90 confidence interval does not include zero, we reject the null hypothesis and can conclude that the average age of PlayStation users is different from the average age of Xbox users.
  C) Because the 90 confidence interval includes zero, we fail to reject the null hypothesis and conclude that the average age of PlayStation users is equal to the average age of Xbox users.
  D) Because the 90 confidence interval does not include zero, we fail to reject the null hypothesis and can conclude that the average age of PlayStation users is different from the average age of Xbox users.

Question 2

If a customer at a particular grocery store uses coupons, there is a 50 probability that the customer will pay with a debit card. Thirty percent of customers use coupons and 35 of customers pay with debit cards.
 
  Given that a customer does not pay with a debit card, the probability that the same customer does not use coupons is ________.A) 0.52
  B) 0.60
  C) 0.77
  D) 0.85

[iceage]

Answer to Question 1

A

Answer to Question 2

C