Unit 7 Quiz Review

1) Suppose we want to test if there is evidence that the true mean of a population is greater than 300.  We randomly select 36 observations from the population and calculate a sample mean of 305 and a sample standard deviation of 20.  What is the test statistic (t-score) for the appropriate hypothesis test?

Initialize the value of 'testStat' below to the hundredths place.

2) We want to test if there is evidence of a difference between two population means.  We randomly sample 35 observations from population 1 and 30 observations from population 2.  The mean and standard deviation of the sample taken from population 1 were 40 and 11, respectively.  The mean and standard deviation of the sample from population 2 were 37 and 9, respectively.  

What is the value for the conservative degrees of freedom for the test?

Initialize the value of 'df' below.

2b) State the test statistic and p-value for the hypothesis test described above.

Initialize the value of 't' and 'p' below.

3) We want to construct a 95% confidence interval for the true mean of a population.  We take a random sample of 6 observations from the population and obtain the following:

3, 5, 8, 4, 10, 12

What is the margin of error for the test?  Initialize the value of 'margin' below.

4) We want to construct a 90% confidence interval for the difference in population means between population A and population B.  We randomly sample 50 observations from population A and obtain a mean of 50 and standard deviation of 4.  We randomly sample 40 observations from population B and obtain a mean of 45 and standard deviation 6.

What is the point estimate (statistic) for the difference in population means (A - B)?

What is the standard error (approximation to the standard deviation of the statistic) that we should use for the confidence interval?

Initialize the value of 'stat' and 'standardError' below.