For each study below, choose the appropriate type of hypothesis test that should be used.

1.A researcher wants to investigate the relationship between the speed of cars on a certain road, and the noise level of that road. They collect the maximum noise level on different streets, and the average speed of cars in mph on those same streets.

2.It is thought that 42% of respondents in a taste test would prefer Hellman's Mayo. In a particular test of 100 people 39% preferred Hellman's Mayo.

3.A population mean is 13. The sample mean is 12.8, and the sample standard deviation is 2. The sample size is 20. Assume the underlying population is normal.

4.A statistics teacher claims that, on the average, 20% of her students get a grade of A, 35% get a grade of B, 25% get a C, 10% get a D, and 10% get an F. She looks at the results of her current class.

5.The College Board reports that in 2016 the mean score on the math SAT was 510 and the standard deviation was 103. A random sample of 20 students who took the test in 2016 had a mean score of 515 and a standard deviation of 111.

6.In a sample drawn from the technology industry, a researcher organizes the data into a table that compares age groups of employees and whether or not they had been promoted in the last 5 years. The researcher is interested in the likelihood of being promoted based on age group.