Exam 12: Inference About a Population

If a sample has 15 observations and a 95% confidence estimate for $\mu$ is needed, the appropriate value of t is 1.753.

As a manufacturer of guitars, a major corporation wants to estimate the proportion of guitar players who are right-handed.How many golfers must be surveyed if they want to be within 0.02, with a 95% confidence? a. Assume that there is no prior information that could be used as an estimate of. b. Assume that the manufacturer has an estimate offound from a previous study, which suggests that 75% of guitar players are right-handed.

The t-test for a population mean is ____________________, meaning that if the population is nonnormal, the results of the test and confidence interval are still valid as long as the nonnormality is not extreme.

The t-distribution allows the calculation of confidence intervals for means for small samples when the population variance is not known, regardless of the shape of the distribution in the population.

If the lower and upper confidence limits of the population proportion p, using a sample of size 1500, are 0.184 and 0.238, respectively, then the lower and upper confidence limits of the total number of successes in the population, given that the population size is 750,000, are respectively:

Applicants' Grades The grades of a sample of 10 applicants, selected at random from a large population, are 71, 86, 75, 63, 92, 70, 81, 59, 80, and 90. -{Applicants' Grades Narrative} Construct a 90% confidence interval estimate for the population standard deviation.

Single Mothers' Ages A random sample of 10 single mothers was drawn from a Obstetrics Clinic.Their ages are 22, 17, 27, 20, 23, 19, 24, 18, 19, and 24 years. -{Single Mothers' Ages Narrative} Estimate the population mean with 90% confidence.