12.16 The report “Mobile Youth Around the World” (The Nielsen Company, December 2010) provided the following information on gender of smartphone users for representative samples of young people age 15 to 24 in several different countries:

Country Percent Female Percent Male United States 55% 45%

Spain 39% 61%

Italy 38% 62%

India 20% 80%

a. Suppose the sample sizes were 1000 for the United States and for India and 500 for Spain and Italy. Complete the following two-way table by entering the observed counts.

Country Female Male United States Spain Italy India

b. Carry out a hypothesis test to determine if there is convincing evidence that the gender proportions are not the same for all four countries. Use a significance level of 0.05. (Hint: See Example 12.7.)