Do male and female servers at Swank Bar work the same number of hours? A sample of 65 female servers worked an average of 26 hours per week, with a standard deviation of 4. A sample of 65 male servers worked an average of 25 hours per week, with a standard deviation of 3. Let μ1μ1 and μ2μ2 represent the typical number of hours worked by all female and male servers at Swank Bar, respectively. Estimate with a 89% confidence level how many more hours female servers work. Round answers to the nearest hundredth

Find the 90% confidence interval for the variance and standard deviation of the ages of students at Arcanum high school if a sample of 24 students has a standard deviation of 2.3 years. Assume the variable is normally distributed.

Scientists collect a simple random sample of 25 menthol cigarettes and 25 non-menthol cigarettes. Both samples consist of cigarettes that are filtered, 100mm long, and non-light. The menthol cigarettes have a mean nicotine amount of 0.87 mg and a standard deviation of 0.24 mg. The non-menthol cigarettes have a mean nicotine amount of 0.92 mg and a standard deviation of 0.25 mg. Use a 0.05 significance level to test the claim that non-menthol cigarettes have greater amounts of nicotine than menthol cigarettes. Assume population variances are not equal.

A sports writer wants to see if a football filled with helium travels farther, on average, than a football filled with air. 12 footballs were filled with helium to the recommend pressure and 15 footballs were filled with air to the recommended pressure. The mean yardage for the helium filled footballs was 267 yards with a standard deviation of 3 yards. The mean yardage for the air filled footballs was 241 yards with a standard deviation of 5 yards. Assume the populations are normal with equal variances. (a). Construct a 99% confidence interval for the mean difference in in yardage for the two types of footballs Lower bound (use 3 decimal places) Upper bound (use 3 decimal places) (b). What can you conclude about the sports writer's idea that helium footballs travel farther, on average? The helium footballs are no different than the other footballs, on average The other footballs travel farther on average than the helium footballs The helium footballs travel farther on average than the…