91影视

Vigorous exercise helps people live several years longer (on average). Whether mild activities like slow walking extend life is not clear. Suppose that the added life expectancy from regular slow walking is just 2 months. A significance test is more likely to find a significant increase in mean life expectancy with regular slow walking if

Step 2: Explanation

A researcher plans to conduct a significance test at the $伪=0.01$ significance level. She designs her study to have a power of $0.90$ at a particular alternative value of the parameter of interest. The probability that the researcher will commit a Type II error for the particular alternative value of the parameter she used is

How much juice? Refer to Exercise 3. The mean amount of liquid in the bottles is $179.6$ml and the standard deviation is $1.3$ml. A significance test yields a $P$-value of $0.0589$. Interpret the $P$-value.

The mean amount of liquid in the bottles is $179.6$ml and the standard deviation is $1.3$ml. A significance test yields a P-value of $0.0589$. Interpret the P-value.

Spinning for apples (5.3 or 6.3) In the 鈥淎sk Marilyn鈥� column of Parade magazine, a reader posed this question: 鈥淪ay that a slot machine has five wheels, and each wheel has five symbols: an apple, a grape, a peach, a pear, and a plum. I pull the lever five times. What are the chances that I鈥檒l get at least one apple?鈥� Suppose that the wheels spin independently and that the five symbols are equally likely to appear on each wheel in a given spin.

a. Find the probability that the slot player gets at least one apple in one pull of the lever.

b. Now answer the reader鈥檚 question.

Don't argue Refer to Exercise 2. Yvonne finds that $96$ of the $150$ students $(64\%)$ say they rarely or never argue with friends. A significance test yields a $P$-value of$0.0291$ Interpret the $P$-value.

Interpreting a $\mathit{P}$-value A student performs a test of $\mathrm{H}0:渭=100H_0:渭=100$versus Ha: $渭>100H_a:渭>100$and gets a $P$-value of $0.044.$The student says, "There is a$0.044$ probability of getting the sample result I did by chance alone." Explain why the student's explanation is wrong.

Interpreting a P-value A student performs a test of $\mathrm{H}0:\mathrm{p}=0.3H_0:p=0.3$versus Ha:$\mathrm{p}<0.3H_a:p<0.3$and gets a $P$-value of $0.22$The student says, "This means there is about a$22\%$chance that the null hypothesis is true." Explain why the student's explanation is wrong.

pg$\underset{炉}{559}$

No homework Refer to Exercises 1 and 9. What conclusion would you make at the$伪=0.05伪=0.05$level?

Attitudes Refer to Exercises 4 and 10 . What conclusion would you make at the $伪=0.05$ level?