a random sample of 23 items is drawn from a population whose standard deviation is unknown. the sample mean is x=770 and the sample standard deviation is s=25 use appendix d to find the values of students t. (a) construct an interval estimate of u with 95% confidence (b) construct an interval estimate of u with 95% confidence assuming that s=50 (c) construct an interval estimate of u with 95% confidence, assuming that s=100.

An IQ test is designed so that the mean is 100 and the standard deviation is 18 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 95​% confidence that the sample mean is within 4 IQ points of the true mean. Assume that σ=18. What is the required sample size and would it be reasonable to sample this amount of students?

An IQ test is designed so that the mean is 100 and the standard deviation is 23 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 95​% confidence that the sample mean is within 7 IQ points of the true mean. Assume that σ=23 and determine the required sample size using technology. Then determine if this is a reasonable sample size for a real world calculation.

Let a population consist of the values 10 cigarettes, 11 cigarettes, and 20 cigarettes smoked in a day. Show that when samples of size 2 are randomly selected with replacement, the samples have mean absolute deviations that do not center about the value of the mean absolute deviation of the population. What does this indicate about a sample mean absolute deviation being used as an estimator of the mean absolute deviation of a population? Calculate the mean absolute deviation for each possible sample of size 2 from the population. Mean Absolute Deviation Sample {10,10} {10,11) {10,20} {11,10} (11,11} {11,20} {20,10} {20,11} {20,20} (Type integers or decimals rounded to one decimal place as needed.) Calculate the mean of the sample mean absolute deviations. The mean of the sample mean absolute deviations is (Type an integer or decimal rounded to one decimal place as needed.) Calculate the population mean absolute deviation. The population mean absolute deviation is. (Type an integer or…

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We want to estimate the mean number of pages per book in the fiction section of the large school library at a 99% confidence level. A sample of 35 fiction books is randomly selected, and the mean number of pages is calculated to be 291.8 pages per book with a standard deviation of 47.6 pages per book.   Use the table to find the appropriate value of t* to use in the given scenario. Enter in the value of t* exactly as you see it written in the table. 1.684 1.697 2.704 2.750

The scores on a test are normally distributed with a mean of 150 and a standard deviation of 30. Find the score that is 2 1/2 standard deviations above the mean.

Let a population consist of the values 9 ​cigarettes, 10 ​cigarettes, and 20 cigarettes smoked in a day. Show that when samples of size 2 are randomly selected with​ replacement, the samples have mean absolute deviations that do not center about the value of the mean absolute deviation of the population. What does this indicate about a sample mean absolute deviation being used as an estimator of the mean absolute deviation of a​ population? Calculate the mean absolute deviation for each possible sample of size 2 from the population. Sample Mean Absolute Deviation   ​{9,9​}     ​{9,10​}     ​{9,20​}     ​{10,9​}     ​{10,10​}     ​{10,20​}     ​{20,9​}     ​{20,10​}     ​{20,20​}

An IQ test is designed so that the mean is 100 and the standard deviation is 18 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 99​% confidence that the sample mean is within 4 IQ points of the true mean. Assume that σ=18 and determine the required sample size using technology. Then determine if this is a reasonable sample size for a real world calculation.   The required sample size is = ?

An IQ test is designed so that the mean is 100 and the standard deviation is 10 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 95​% confidence that the sample mean is within 2 IQ points of the true mean. Assume that σ=10 and determine the required sample size using technology. Then determine if this is a reasonable sample size for a real world calculation.