1) Use the normal distribution to find a confidence interval for a proportion p given the relevant sample results. Give the best point estimate for p, the margin of error, and the confidence interval. Assume the results come from a random sample. A 99% confidence interval for p given that p^=0.8 and n=140

Round your answer for the point estimate to two decimal places, and your answers for the margin of error and the confidence interval to three decimal places. Point estimate = Margin of error = The 99% confidence interval is

2) Use the normal distribution to find a confidence interval for a proportion p given the relevant sample results. Give the best point estimate for p, the margin of error, and the confidence interval. Assume the results come from a random sample. A 99% confidence interval for the proportion of the population in Category A given that 20% of a sample of 450 are in Category A. Point estimate = Margin of error = The 99% confidence interval is

3) What sample size is needed to give a margin of error within 1% in estimating a population proportion with 99% confidence? Round your answer up to the nearest integer. Sample size =

4) How Many Household Cats Hunt Birds? "Domestic cats kill many more wild birds in the United States than scientists thought," states a recent article.¹ Researchers used a sample of n=140 households in the US with cats to estimate that 35% of household cats in the US hunt outdoors.

¹Milius, S., "Cats kill more than one billion birds each year," Science News, 183(4), February 23, 2013, revised March 8, 2014. Data approximated from information give in the article.

(a) Find a 90% confidence interval for the proportion of household cats in the US that hunt outdoors. Round your answers to three decimal places. The 90% confidence interval?

5) Democrat or Republican? 2011 A survey of 15,000 American adults in 2011 found that 35.3% identify as Democrats and 34.0% identify as Republicans, with the rest identifying as independent or other.¹ If we want 99% confidence, what are the margins of error in the estimate for the proportion of Democrats and for the proportion of Republicans? Round your answers to four decimal places.

6) Comparing Normal and Bootstrap Confidence Intervals Find a 95% confidence interval for the proportion two ways, using StatKey or other technology and percentiles from a bootstrap distribution and using the normal distribution and the formula for standard error. Proportion of home team wins in soccer, using p^=0.583 with n=120 Click here to access StatKey. Round your answers to three decimal places.

Bootstrap:

Normal:

7) Use the t-distribution to find a confidence interval for a mean given the relevant sample results. Give the best point estimate for , the margin of error, and the confidence interval. Assume the results come from a random sample from a population that is approximately normally distributed. A 95% confidence interval for using the sample results x=12.4, s=5.7, and n=30 Round your answer for the point estimate to one decimal place, and your answers for the margin of error and the confidence interval to two decimal places.

point estimate = margin of error =

The 95% confidence interval is

8) Use the t-distribution to find a confidence interval for a mean given the relevant sample results. Give the best point estimate for , the margin of error, and the confidence interval. Assume the results come from a random sample from a population that is approximately normally distributed. A 99% confidence interval for using the sample results x=49.2, s=14.7, and n=10 Round your answer for the point estimate to one decimal place, and your answers for the margin of error and the confidence interval to two decimal places.

point estimate = margin of error = The 99% confidence interval is

9)What sample size is needed to give a margin of error within 1 in estimating a population mean with 90% confidence, assuming a previous sample had s=2.9. Round your answer up to the nearest integer

sample size =

10) How Many Birds Do Domestic Cats Kill? "Domestic cats kill many more wild birds in the United States than scientists thought," states a recent article.¹ Researchers used a sample of n=140 households in the US with cats to estimate that 35% of household cats in the US hunt outdoors. A separate study² used KittyCams to record all activity of n=55 domestic cats that hunt outdoors. The video footage showed that the mean number of kills per week for these cats was 2.4 with a standard deviation of 1.51. Find a 90% confidence interval for the mean number of kills per week by US household cats that hunt outdoors. Round your answers to three decimal places.

The 90 confidence interval is