According to a report on sleep deprivation by the Centers for Disease Control and Prevention, the percent of California residents who reported insufficient rest or sleep during each of the preceding 30 days is 7.6%, while this percent is 9% for Oregon residents. These data are based on simple random samples of 11848 California and 4571 Oregon residents. Calculate a 95% confidence interval for the difference between the proportions of Californians and Oregonians who are sleep deprived. Round your answers to 4 decimal places. Make sure you are using California as Group A and Oregon as Group B.

In a survey, 24 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $36 and standard deviation of $15. Construct a confidence interval at a 90% confidence level.

A random sample of high school students is used to estimate the mean time all high school students study for Algebra II tests. A 99% confidence interval based on this sample is: 1.7 hours to 3.1 hours.  What is the sample mean?

In a survey, 10 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $46 and standard deviation of $8. Construct a confidence interval at a 99% confidence level.Give your answers to one decimal place.

Suppose we wish to estimate the average number of hours per week that Americans watch TV. Use the following data from an SRS to find a 90% confidence interval: 30        64        49        40        21        58        9          43        39            43

A survey is taken of 250 students, and a P of 0.45 is found. The same survey is repeated with 1,000 students, and the same value is found. Compare the two 95% confidence intervals. What is the relationship? Is the margin of error for the second one four times smaller? How much smaller is it?

In a survey, 14 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $36 and standard deviation of $16. Construct a confidence interval at a 99% confidence level. Give your answers to one decimal place.

A survey of 32,782 adults in 2004 indicated that 24.6% of adults were current smokers. A similar study conducted in 1995 of 40,000 adults indicated that 29.7% were current smokers. a. Find and interpret a point estimate of the difference between the proportion of current smokers in 1995, and the proportion of current smokers in 2004. b. A 95% confidence interval for the true difference is (-0.058,-0.045). Interpret. c. What assumptions must you make for the confidence interval i part b to be valid? (…) a. Find a point estimate of the difference between the proportion of current smokers in 1995 and the proportion of current smokers in 2004. (Round to three decimal places as needed.)

You measure the weights of 41 textbooks and find they have a mean weight of 77 ounces. The standard deviation for weights of all textbooks is 5.1 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight. Give your answers as decimals, to two places