(10 points) A retailer of smart phones wants to understand whether or not the phone preference of customers is independent of gender.

(10 points) A retailer of smart phones wants to understand whether or not the phone preference of customers is independent of gender. She surveys a sample of 600 customers and creates the following contingency table:

 Android Apple Other Total

Men 115 80 135 330

Women 75 100 95 270

Total     190       185     225 600

a) (2 pts) Complete the following table of expected frequencies:

 Android Apple Other

Men 104.50 101.75 

Women 85.50 101.25

b) (3 pts) Give the null and alternative hypotheses for the contingency analysis:

c) (2 pts) The value of the test statistic is 11.717 with a p-value of 0.003. At a 5% significance level, do you reject the null hypothesis? Explain why or why not using either the critical statistic method or the p-value method (your choice).

d) (3 pts) What is the business implication of your conclusion in step c above?