The home run percentage is the number of home runs per 100 times at bat. A random sample of 43 professional baseball players gave the following data for home run percentages.

(a) Use a calculator with mean and standard deviation keys to find x and s. (Round your answers to two decimal places.)

(b) Compute a 90% confidence interval for the population mean μ of home run percentages for all professional baseball players. Hint: If you use the Student's t distribution table, be sure to use the closest d.f. that is smaller. (Round your answers to two decimal places.)

(c) Compute a 99% confidence interval for the population mean μ of home run percentages for all professional baseball players. (Round your answers to two decimal places.)

(d) The home run percentages for three professional players are below.

Examine your confidence intervals and describe how the home run percentages for these players compare to the population average.

A.) We can say Player A falls close to the average, Player B is above average, and Player C is below average.

B.) We can say Player A falls close to the average, Player B is below average, and Player C is above average.    

C.) We can say Player A and Player B fall close to the average, while Player C is above average.

D.) We can say Player A and Player B fall close to the average, while Player C is below average.

(e) In previous problems, we assumed the x distribution was normal or approximately normal. Do we need to make such an assumption in this problem? Why or why not? Hint: Use the central limit theorem.

A.) Yes. According to the central limit theorem, when n ≥ 30, the x distribution is approximately normal.

B.) Yes. According to the central limit theorem, when n ≤ 30, the x distribution is approximately normal.    

C.) No. According to the central limit theorem, when n ≥ 30, the x distribution is approximately normal.

D.) No. According to the central limit theorem, when n ≤ 30, the x distribution is approximately normal.

A polling organization is asked to determine the percentage of Americans who exercise at least twice per week. The error tolerance is two and a half percentage points, and the confidence level applied to the result is 95%. Lacking any other information, what is the minimum number of people the pollsters must interview in order to satisfy these constraints?

The Centers for Disease Control reported the percentage of people 18 years of age and older who smoke (CDC website, December 14, 2014). Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .29. a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of .02 (rounded up to the next whole number)? Use 95% confidence. b. Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers. What is the point estimate of the proportion of smokers in the population (to 4 decimals)? c. What is the 95% confidence interval for the proportion of smokers in the population (to 4 decimals)?

What is the percentage of people living with an income below the federal poverty level?
What is the number of cases of Emergency Department visits for Asthma in the 5-17 year?
Select one neighborhood from each of the other 4 Boroughs and compare with your neighborhood (create a table

)

17% of all college students volunteer their time. Is the percentage of college students who are volunteers smaller for students receiving financial aid? Of the 329 randomly selected students who receive financial aid, 39 of them volunteered their time. What can be concluded at the αα = 0.05 level of significance?

1. For this study, we should use Select an answer z-test for a population proportion t-test for a population mean
2. The null and alternative hypotheses would be:   

H0:H0:  ? μ p  Select an answer = < > ≠   (please enter a decimal)   

H1:H1:  ? μ p  Select an answer = ≠ > <   (Please enter a decimal)

3. The test statistic ? z t  =  (please show your answer to 3 decimal places.)
4. The p-value =  (Please show your answer to 4 decimal places.)
5. The p-value is ? > ≤  αα
6. Based on this, we should Select an answer fail to reject accept reject  the null hypothesis.
7. Thus, the final conclusion is that ...
   • The data suggest the population proportion is not significantly lower than 17% at αα = 0.05, so there is insufficient evidence to conclude that the percentage of financial aid recipients who volunteer is lower than 17%.
   • The data suggest the population proportion is not significantly lower than 17% at αα = 0.05, so there is sufficient evidence to conclude that the percentage of financial aid recipients who volunteer is equal to 17%.
   • The data suggest the populaton proportion is significantly lower than 17% at αα = 0.05, so there is sufficient evidence to conclude that the percentage of financial aid recipients who volunteer is lower than 17%.

1. We are interested in comparing the percentage of females versus males who feel they are overweight. The following data was collected:
   1. What is the 95% confidence interval for the difference in proportion between women and men?
   2. What is the test statistic?

Please find (online) and explain an example of a real life percentage, and a real life example of a rate OR ratio. You will want to find examples that come from real research (a Google search will be helpful). How are these statistics useful? What are the limitations of each (if any)?

Posts should be approximately 100 words.

Let x be a random variable that represents the percentage of successful free throws a professional basketball player makes in a season. Let y be a random variable that represents the percentage of successful field goals a professional basketball player makes in a season. A random sample of n = 6 professional basketball players gave the following information.

(e) Find a 90% confidence interval for y when x = 70. (Round your answers to one decimal place.)

(f) Use a 5% level of significance to test the claim that β > 0. (Round your answers to two decimal places.)

Find the most recent federal deficit as a percentage of GDP of the United States. Suppose that the federal budget deficit was eliminated and there was no change in private saving. What would be the effect on the long run capital stock per worker? What would be the effect on long run output per worker?