An economist wants to find a 90% confidence interval for the mean sale price of houses in a state. How large a sample should she select so that the estimate is within $3500 of the population mean? Assume that the standard deviation for the sale prices of all houses in this state is $31,500.
answer is 221 but unsure of how to get this answer
We are given population standard deviation and hence we use Z score to find sample size and Sample size we calculated is 221 which is the answer. Hence Answer is Sample Size = 221
An economist wants to find a 90% confidence interval for the mean sale price of houses...
Please answer this question.. A marketing researcher wants to find a 95% confidence interval for the mean amount that visitors to a theme park spend per person per day. She knows that the standard deviation of the amounts spent per person per day by all visitors to this park is $11. How large a sample should the researcher select so that the estimate will be within $2 of the population mean? 2,
A researcher wants to determine a 99% confidence interval for the mean number of hours that adults spend per week doing community service. How large a sample should the researcher select so that the estimate is within 1.4 hours of the population mean? Assume that the standard deviation for time spent per week doing community service by all adults is 3 hours.
An economist wants to estimate the mean per capita income (in thousands of dollars) for a major city in California. Suppose that the mean income is found to be $24.3$24.3 for a random sample of 758758 people. Assume the population standard deviation is known to be $9.2$9.2. Construct the 90%90% confidence interval for the mean per capita income in thousands of dollars. Round your answers to one decimal place.
Annie is a researcher who wants to find a confidence interval estimate of the mean time it takes to complete an order over the phone at a call center for a large retail company. She has selected a random sample of 18 orders and recorded the time to complete the order. The sample mean time was 4.27 minutes and the sample standard deviation was 0.78 minutes. Assuming the conditions needed for inference are met,which of the following is the appropriate...
Kim wants to determine a 90 percent confidence interval for the true proportion of high school students in the area who attend their home basketball games. How large of a sample must she have to get a margin of error less than 0.02? [Note that you don't have an estimate for p*!] [Round to the smallest integer that works.] n =
We want to estimate the population mean within 21, with a 90% level of confidence. The population standard deviation is estimated to be 60. How large a sample is required?
An economist wants to estimate the mean per capita income (in thousands of dollars) for a major city in Texas. Suppose that the mean income is found to be $18.7 for a random sample of 953 people. Assume the population standard deviation is known to be $8.6 Construct the 85% confidence interval for the mean per capita income in thousands of dollars. Round your answers to one decimal place.
Suppose Mi-Young wants to estimate the mean salary for state employees in Alabama. She obtains a list of all state employees and randomly selects 12 of them. She plans to obtain the salaries of these 12 employees and construct a ?- confidence interval for the mean salary of all state employees in Alabama. Have the requirements for a one-sample ? ‑confidence interval for a mean been met? The requirements been met because have not the population is not normal. the...
A researcher wants to estimate the mean IQ score for a population of high school students. How many students will she have to select for the IQ tests if she wants 95% confidence the sample mean is within 3 IQ points of the population mean? Assume the population standard deviation is 15.
5. The following is a 90% confidence interval for p:(0.26, 0.54). How large was the sample used to construct this interval? (10%) 6. If you wish to estimate a population mean to within 0.2 using a 95% confidence interval and you know from prior sampling that q? is approximately equal to 5.4, how many observations would you have to include in your sample? (10%)