You would like to construct a 99% confidence interval to estimate the population mean price of milk (per gallon) in your city. You select a random sample of prices from different stores. The sample has a mean of 3.49 dollars and a standard deviation of 0.28 dollars.(a) What is the best point estimate, based on the sample, to use for the population mean?dollars(b) For each of the following sampling scenarios, determine which distribution should be used to calculate the critical value for the 99% confidence interval for the population mean.(In the table, Z refers to a standard normal distribution, and t refers to a t distribution.)Sampling scenario Z t Could use either Z or t UnclearThe sample has size 19, and it is from a normally distributed population with a known standard deviation of 0.31. Zt The sample has size 14, and it is from a normally distributed population with an unknown standard deviation. Zt The sample has size 80, and it is from a non-normally distributed population. Zt CheckSave For LaterSubmit Assignment

You would like to construct a 95% confidence interval to estimate the population mean annual income for people over age 40 in your state. You choose a random sample of such incomes and compute the mean of the sample as 40,295.5 dollars with a standard deviation of 7563.4 dollars.(a) What is the best point estimate, based on the sample, to use for the population mean?dollars(b) For each of the following sampling scenarios, determine which distribution should be used to calculate the critical value for the 95% confidence interval for the population mean.(In the table, Z refers to a standard normal distribution, and t refers to a t distribution.)Sampling scenario Z t Could use either Z or t UnclearThe sample has size 15, and it is from a population with a distribution about which we know very little. Zt The sample has size 85, and it is from a non-normally distributed population with a known standard deviation of 7752. Zt The sample has size 20, and it is from a normally distributed population with an unknown standard deviation. Zt CheckSave For LaterSubmit Assignment

As part of an annual review of its accounts, a discount brokerage selected a random sample of 26 customers and reviewed the value of their accounts. The mean was $32,100, with a sample standard deviation of $8,550. (Use t Distribution Table & z Distribution Table.)What is a 95% confidence interval to estimate the mean account value of the population of customers? (Round your answers to the nearest dollar amount.)

Let’s say you wish to construct a sampling distribution of sample size 100 for the proportion of people that voted for AAP. Suppose the population standard deviation is known to be 0.7, what is the interval in which the mean of the sampling distribution will belong at a 90% confidence level?(0.485, 0.675) (0.572, 0.588)(0.465, 0.695)(0.503, 0.657)

You want to compute a 90% confidence interval for the mean of a population with unknown standard deviation. The sample size is 30. The correct distribution value for calculating the required confidence interval is:-Group of answer choices1.961.64491.6991.6971.311

A researcher wishes to construct a 95% confidence interval for a population mean. She selects a simple random sample of size 8 from the population. The population is normally distributed and σ is unknown. When constructing the confidence interval estimate, the researcher uses the distribution value from the normal distribution (in Minitab). The confidence level of her resulting confidence interval estimate will beGroup of answer choicesExactly 95%Greater than 95%Less than 90%Exactly 90%Less than 95% but greater than 90%.