91影视

In Exercises 5鈥�8, use the given information to find the number of degrees of freedom, the critical values ${蠂}_L^2$and${蠂}_R^2$, and the confidence interval estimate of $蟽$. The samples are from Appendix B and it is reasonable to assume that a simple random sample has been selected from a population with a normal distribution.

Weights of Pennies 95% confidence;n= 37,s= 0.01648 g.

Using Correct Distribution. In Exercises 5鈥�8, assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) Find the critical value $t_{\frac{伪}{2}}$,(b) find the critical value $z_{\frac{伪}{2}}$,or (c) state that neither the normal distribution nor the t distribution applies.

Denver Bronco Salaries confidence level is 90%, $蟽$is not known, and the histogram of 61 player salaries (thousands of dollars) is as shown.

Finding Critical Values. In Exercises 5鈥�8, find the critical value that corresponds to the given confidence level.

99%

Finding Critical Values. In Exercises 5鈥�8, find the critical value that corresponds to the given confidence level.

99.5%

In Exercises 5鈥�8, use the relatively small number of given bootstrap samples to construct the confidence interval. Freshman 15: Here is a sample of amounts of weight change (kg) of college students in their freshman year (from Data Set 6 鈥淔reshman 15鈥� in Appendix B): 11, 3, 0, -2, where -2 represents a loss of 2 kg and positive values represent weight gained. Here are ten bootstrap samples: {11, 11, 11, 0}, {11, -2, 0, 11}, {11, -2, 3, 0}, {3, -2, 0, 11}, {0, 0, 0, 3}, {3, -2, 3, -2}, {11, 3, -2, 0}, { -2, 3, -2, 3}, { -2, 0, -2, 3}, {3, 11, 11, 11}. a. Using only the ten given bootstrap samples, construct an 80% confidence interval estimate of the mean weight change for the population. b. Using only the ten given bootstrap samples, construct an 80% confidence interval estimate of the standard deviation of the weight changes for the population.

In Exercises 5鈥�8, use the given information to find the number of degrees of freedom, the critical values X2 L and X2R, and the confidence interval estimate of $蟽$. The samples are from Appendix B and it is reasonable to assume that a simple random sample has been selected from a population with a normal distribution.

Platelet Counts of Women 99% confidence;n= 147,s= 65.4.

Finding Critical Values. In Exercises 5鈥�8, find the critical value $z_{\frac{伪}{2}}$that corresponds to the given confidence level.

98%

Formats of Confidence Intervals.

In Exercises 9鈥�12, express the confidence interval using the indicated format. (The confidence intervals are based on the proportions of red, orange, yellow, and blue M&Ms in Data Set 27 鈥淢&M Weights鈥� in Appendix B.)

Red M&Ms Express 0.0434 < p < 0.217 in the form of$p+E$

Confidence Intervals. In Exercises 9鈥�24, construct the confidence interval estimate of the mean.

Birth Weights of Girls Use these summary statistics given in Exercise 8:$\mathbf{n}鈥�\mathbf{=}鈥�\mathbf{205}\mathbf{,}\stackrel{\mathbf{炉}}{\mathbf{x}}鈥�\mathbf{=}\mathbf{30}\mathbf{.}\mathbf{4}鈥�\mathbf{hg}\mathbf{,}\mathbf{s}鈥�\mathbf{=}\mathbf{7}\mathbf{.}\mathbf{1}鈥�\mathbf{hg}$. Use a 95% confidence level. Are the results very different from those found in Example 2 with only 15 sample values?