Q:

# Suppose that a recent article stated that the mean time spent in jail by a first-time convicted burglar is 2.5 years. A study was then done to see if the mean time has increased in the new century. A random sample of 27 first-time convicted burglars in a recent year was picked. The mean length of time in jail from the survey was four years with a standard deviation of 1.9 years. Suppose that it is somehow known that the population standard deviation is 1.4. Conduct a hypothesis test to determine if the mean length of jail time has increased. Assume the distribution of the jail times is approximately normal. Since both ơ and sx are given, which should be used? O σ O sx In one to two complete sentences, explain why?

Accepted Solution

A:
Answer:bar xStep-by-step explanation:The variable in this test is the mean length of time that the burglars  would spend in . The symbol is x-bar x-bar = 4s = 1.4n= 27null: u = 2.5h1; u ≠ 2.54-2.5/(1.9/√27)= 1.5/(1.4/5.196)= 1.5/0.2694= 5.57z critical = 1.6445z > z criticalwe reject the null hypothesis