According to the Census Bureau 13 of American adults aged 18

According to the Census Bureau, 13% of American adults (aged 18 and over) are Hispanic. An opinion poll plans to contact an SRS of 1200 adults. What is the mean number of Hispanics in such samples? What is the standard deviation? Should we be suspicious if the sample selected for the opinion poll contains 15% Hispanic people? Compute an appropriate probability to support your answer.

Solution

p=0.13
q=0.87
n=1200

in binomial distribution:

mean=np=156
S.D=npq=135.72