Exam 6: Estimates and Sample Sizes With One Sample

For the next questions, assume that a simple random sample has been taken and the population is normally distributed. Engineers assessing the variation in wait time at Starbucks, Dunkin Donuts, and Caribou Coffee determined that the standard deviation of the wait time for a sample of nine customers was 25.6 seconds. Use a 95% confidence level. -Find the margin of error E that corresponds to the above statistics and confidence level.

For the next questions, determine which is the correct distribution. -99% Confidence Interval for . The sample data appear to come from a normally distributed population.

For the next questions, assume that a simple random sample has been taken and the population is normally distributed. Engineers assessing the variation in wait time at Starbucks, Dunkin Donuts, and Caribou Coffee determined that the standard deviation of the wait time for a sample of nine customers was 25.6 seconds. Use a 95% confidence level. -Find the critical value .

For the next questions, find the critical value that corresponds to the given confidence level. -98%; is unknown ; population appears to be normally distributed

For the next questions, determine which is the correct distribution. -95% Confidence Interval for . The sample data appear to come from a normally distributed population.

Find the minimum sample size required to estimate a population mean -Find the margin of error E that corresponds to the above statistics and confidence level.

For the next questions, find the critical value that corresponds to the given confidence level. -95%; is unknown ; population appears to be normally distributed

Find the minimum sample size required to estimate a population proportion p . -Find the margin of error E that corresponds to the above statistics and confidence level.

Use the following confidence level interval limits to find the point estimate ˆp and the margin of error E . -As part of a restoration project at a wetland, biologists planted Lyngbye's sedge shoots. After one year, they find the confidence interval of the proportion of surviving shoots from .648 to .752 actually does contain the true value of p .