Question

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 36 arrests last month, 28 were of males aged 15 to 34 years. Use a 5% 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.)

(c) Find the P-value of the test statistic. (Round your answer to four decimal places.)

2The Toylot company makes an electric train with a motor that it claims will draw an average of only 0.8 ampere (A) under a normal load. A sample of nine motors was tested, and it was found that the mean current was x = 1.40 A, with a sample standard deviation of s = 0.45 A. Do the data indicate that the Toylot claim of 0.8 A is too low? (Use a 1% level of significance.)

***What is the the value of the sample test statistic? (Round your answer to three decimal places.)

3.Professor Jennings claims that only 35% of the students at Flora College work while attending school. Dean Renata thinks that the professor has underestimated the number of students with part-time or full-time jobs. A random sample of 82 students shows that 37 have jobs. Do the data indicate that more than 35% of the students have jobs? Use a 5% level of significance.

****What is the value of the sample test statistic? (Round your answer to two decimal places.)


(c) Find (or estimate) the P-value.

P-value > 0.2500

.125 < P-value < 0.250   

  0.050 < P-value < 0

.1250.025 < P-value < 0.0500

.005 < P-value < 0.025

P-value < 0.005

Answer 1