Description
8. The prices in dollars for a particular model of camera are shown below for 10 online retailers. Estimate the true mean price for this particular camera with 95% confidence. Assume normal distribution. 225, 240, 215, 206, 211, 210, 193, 250, 225, 202. Please round to the nearest tenth and write your answer in the form ( , ); for example (31,34) or (25,46). Do not type in any extra spaces.
9. Assume that we want to construct a confidence interval. Determine whether you should use the t-distribution or the normal distribution to find it, based off of the following information. In this problem, let n be the sample size. n = 23, the standard deviation is unknown, the population appears to be normally distributed
o T-Distribution
o Normal Distribution
o neither of the methods studied by us can be used
10. Assume that we want to construct a confidence interval. Determine whether you should use the t-distribution or the normal distribution to find it, based off of the following information. In this problem, let n be the sample size.
n = 200, the standard deviation is 15, the population appears to be skewed
T-Distribution
Normal Distribution
neither of the methods studied by us can be used
11. Assume that we want to construct a confidence interval. Determine whether you should use the t-distribution or the normal distribution to find it, based off of the following information. In this problem, let n be the sample size.
n = 5, the standard deviation is known, the population appears to be very skewed
neither of the methods studied by us can be used
Normal Distribution
t-distribution
12. Assume that we want to construct a confidence interval. Determine whether you should use the t-distribution or the normal distribution to find it, based off of the following information. In this problem, let n be the sample size n = 200, the standard deviation is unknown, the population appears to be normally distributed
T-Distribution
Normal Distribution
13. 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?
14. If the variance of a national accounting examination is 900, how large a sample is needed to estimate the true mean score within 5 points with 99% confidence?