Laura Strubel is reviewing some data from a marketing research project that shows the age of persons who frequently purchase her company's product, Strubel's Gourmet Seafood frozen dinners. Laura is considering buying radio time for a new ad campaign, and knowing the age of the target market would be very helpful to her in selecting which programs to place the ads. Laura sees that the mean age of frequent buyers is 45 with a standard deviation of 12. She correctly interprets this to mean that about 70 percent (68 percent to be exact)of her target market is aged from:
A) 18 to 45
B) 45 to 68
C) 33 to 57
D) 20 to 32
E) 45 to 57

Question

Quizplus · Accepted Answer

Since the standard deviation is 12, we can use the empirical rule to determine the range of ages that fall within one standard deviation of the mean. According to the empirical rule, about 68% of the data falls within one standard deviation of the mean.

So, 68% of frequent buyers would have an age between:

Mean - Standard deviation = 45 - 12 = 33

and

Mean + Standard deviation = 45 + 12 = 57

Thus, the correct answer is C, 33 to 57.

Laura Strubel Is Reviewing Some Data from a Marketing Research