In: Statistics and Probability
part A : Is the national crime rate really going down? Some sociologists say yes! They say that the reason for the decline in crime rates in the 1980s and 1990s is demographics. It seems that the population is aging, and older people commit fewer crimes. According to the FBI and the Justice Department, 70% of all arrests are of males aged 15 to 34 years†. Suppose you are a sociologist in Rock Springs, Wyoming, and a random sample of police files showed that of 35 arrests last month, 22 were of males aged 15 to 34 years. Use a 1% level of significance to test the claim that the population proportion of such arrests in Rock Springs is different from 70%.
What is the value of the sample test statistic? (Round your
answer to two decimal places.)
Find the P-value of the test statistic. (Round your answer
to four decimal places.)
part B: What is your favorite color? A large survey of countries, including the United States, China, Russia, France, Turkey, Kenya, and others, indicated that most people prefer the color blue. In fact, about 24% of the population claim blue as their favorite color.†Suppose a random sample of n = 52 college students were surveyed and r = 9 of them said that blue is their favorite color. Does this information imply that the color preference of all college students is different (either way) from that of the general population? Use α = 0.05.
What is the value of the sample test statistic? (Round your
answer to two decimal places.)
(c) Find the P-value of the test statistic. (Round your
answer to four decimal places.)