We have given here,
Population standard deviation = $600
Margin of error =E=$125
Level of significance =1-0.90=0.1
Z critical value is (by using Z table)=1.645
Sample size formula is
=62.35
Sample size ![]() |
9. A county tax assessor wants to estimate within $125 the average property tax bill for...
(Extra Credit): A tax assessor wants to assess the mean property tax bill for all homeowners in East Lansing, Michigan. A past survey done a few years ago yielded a sample mean and standard deviation of 3000.00 and 1500.00 dollars respectively. How many tax records should be sampled for a margin of error of at most $200 at a confidence level of a = 0.93. O A: 162 B: 374 O C: 185 OD: 217 O E: 265
The real estate assessor for a county government wants to study various characteristics of single-family houses in the county. A random sample of 49 houses reveals the following: Heated area of the houses (in square feet): = 1720, S = 350 a. Construct a 90% confidence interval estimate for the population mean heated area of the houses. b. Interpret the interval constructed in (a).
A researcher with North County Transit wishes to estimate the mean one-way commute distance for students who attend Palomar College. She wants to construct a 98% confidence interval for the distance to within 2 miles. How large of a sample must she take? Assume that commute distances are normally distributed with a standard deviation of 10.2 miles.
A researcher with North County Transit wishes to estimate the mean one-way commute distance for students who attend Palomar College. She wants to construct a 98% confidence interval for the distance to within 2 miles. How large of a sample must she take? Assume that commute distances are normally distributed with a standard deviation of 10.2 miles.
6. A researcher with North County Transit wishes to estimate the mean one-way commute distance for students who attend Palomar College. She wants to construct a 98% confidence interval for the distance to within 2 miles. How large of a sample must she take? Assume that commute distances are normally distributed with a standard deviation of 10.2 miles.
(b) A medical statistician wants to estimate the average weight loss of people who are on a new diet plan. In a preliminary study, he guesses that the standard deviation of the population of weight losses is about 10 pounds. How large a sample should he take to estimate the mean weight loss to within 2 pounds, with 90% confidence.
A surveyor wants to estimate the average income of daily users of a transit service. The surveyor would like to estimate this value to within $1,000 of the true mean with 90 percent confidence. If historic data indicates that the standard deviation for the sample estimates will be $30,000, what is the minimum sample size to estimate the mean income if the total population is 5,000 riders per day? When the actual sample was taken, the sample standard deviation was...
If the inspection division of a county weights and measures department wants to estimate the mean amount of soft-drink fill in 2-liter bottles to within ± 0.02 liter with 90% confidence and also assumes that the standard deviation is 0.07 liters, what sample size is needed?
Question 13 D 1 pts A university of dean of students wishes to estimate the average number of hours students spend doing homework per week. The standard deviation from a previous study is 6.2 hours. How large a sample must be selected if he wants to be 99% confident of finding whether the true mean differs from the sample mean by 1.5 hours? 1 pts Question 14 If the variance of a national accounting examination is 900, how large a...
3. A random sample of 76 three-year olds attending daycare showed that the yearly tuition average is $5648. Assume the population standard deviation is known to be $630. Find the 98% confidence interval of the mean yearly daycare tuition 4. A researcher is interested in estimating the average monthly salary of sports reporters in a large city. He wants to be 90% confident with his estimate. If the standard deviation is $1500, how large of a sample is needed to...