Of all individual tax returns, 37 percent include errors made by the taxpayer. If IRS examiners are assigned randomly selected returns in batches of 12, find the mean and standard deviation for the number of erroneous returns per batch.
A) μ = 2.80, σ = 1.67
B) μ = 4.44, σ = 1.67
C) μ = 4.44, σ = 2.80
D) μ = 7.56, σ = 2.80

Question

Quizplus · Accepted Answer

Mean = np = 12(.37) = 4.44
Standard Deviation === 1.67

Of All Individual Tax Returns, 37 Percent Include Errors Made