Question: 10 Define the parameter of interest, then use it to write the null and alternative hypothesis (in symbols) for each of the following research questions.

a. Many cars have a recommended tire pressure of 32psi (pounds per square inch). At a roadside vehicle safety checkpoint, officials plan to randomly select 50 cars for which this is the recommended tire pressure and measure the actual tire pressure in the front left tire. They want to know whether drivers on average have too little pressure in their tires.

b. The box of Yvette’s favorite cereal states that the net contents weigh 12 ounces. Yvette is suspicious of this claim because the package never seems full to her. She plans to measure the weight of the contents of the next 20 boxes she buys and find out whether she is being shore- changed.

c. Nonprofit hospitals must provide a certain amount of charity care to maintain nonprofit, tax- exempt status. Although the amount differs by area, let’s suppose that all such hospitals are required to provide charity services equivalent to 4% of net patient revenue. A legislator is concerned that there is inadequate enforcement of this regulation. He plans to audit a random sample of 30 nonprofit hospitals and assess the percentage of net patient revenue they spend on charity care. He will then test whether the population mean is a least 4%.