When surveyed for brand recognition, 98% of consumers recognize Coke. A new survey of 800 randomly selected consumers is to be conducted. For such a group of 800, determine the mean and standard deviation for the number who recognize the Coke brand name. Considering as unusual a result that differs from the mean by more than two standard deviations, it ( (is/is not) ) unusual to get 790 consumers who recognize the Coke brand name.
A) 16, 3.96, is not
B) 16, 16, is
C) 784, 3.96, is not
D) 784, 3.96, is
E) None of the choices are correct

Question

Quizplus · Accepted Answer

The mean is calculated as np = 800 * 0.98 = 784. The standard deviation is sqrt(np(1-p)) = sqrt(800 * 0.98 * 0.02) ≈ 3.96. A result of 790 is within two standard deviations of the mean (784 ± 2*3.96), so it is not unusual.

When Surveyed for Brand Recognition, 98% of Consumers Recognize Coke