Entertainment Software Association Would Like to Test If the Average

Entertainment Software Association would like to test if the average age of "gamers" (those that routinely play video games) is more than 30 years old. A random sample of 33 gamers was selected and their ages were recorded. Assume that the standard deviation for the population of the age of gamers is 4.7 years and the true population mean for the age of gamers is 31.2 years. Using α = 0.02, beta equals ______.

A) 0.7224
B) 0.0434
C) 0.2918
D) 0.1247