In a recent study, 1,115 males 25 to 35 years of age were randomly chosen and asked about their exercise habits. Based on the study results, the researchers estimated the mean time that a male 25 to 35 years of age spends exercising with 90%, 95%, and 99% confidence intervals. These were (not necessarily in the same order):For which of the three intervals do you have the most confidence that it captures the population mean (μ)?(3, 4)(2.5, 4.5)(2, 5)The confidence interval in which you have the most confidence that it captures the population mean μ must be:the 90% confidence intervalthe 95% confidence intervalthe 99% confidence intervalWhich of the three confidence intervals provides the most precise estimation?(3, 4)(2, 5)(2.5, 4.5)The confidence interval that provides the most precise estimation, must be:the 99% confidence intervalthe 95% confidence intervalthe 90% confidence interval

A student was asked to find a 95% confidence interval for weight of their backpacks in pounds using data from a random sample of size n = 20. Which of the following is a correct interpretation of the interval 3.1 < μ < 8.6? Assume the population is normally distributed.With 95% confidence, the weight of a randomly selected backpack will be between 3.1 and 8.6 pounds.There is a 95% chance that the mean of a sample of 20 backpacks will weigh between 3.1 and 8.6 pounds.There is a 95% chance that the weight is between 3.1 and 8.6.With 95% confidence, the mean weight of all backpacks is between 3.1 and 8.6 pounds.The sample mean weight of all backpacks is between 3.1 and 8.6 pounds, 95% of the time. We know this is true because the mean of our sample is between 3.1 and 8.6.

Suppose (35,40) is a 95% confidence interval estimate for a population mean 𝜇. Which of the following are true statements?I. There is a .95 probability that 𝜇 is between 35 and 40.II. If 100 random samples of the given size are picked and a 95% confidence interval is calculated from each, then 𝜇 will be in 95 of the resulting intervals.III. If 95% confidence intervals are calculated from all possible samples of the given size, 𝜇 will be in 95% of these intervals.I and III and IIIII and IIII, II, and IIINone of the above gives the complete set of true responses.

A student was asked to find a 98% confidence interval for widget width using data from a random sample of size n = 27. Which of the following is a correct interpretation of the interval 13.5 < μ < 22?Check all that are correct.There is a 98% chance that the mean of the population is between 13.5 and 22.With 98% confidence, the mean width of a randomly selected widget will be between 13.5 and 22.There is a 98% chance that the mean of a sample of 27 widgets will be between 13.5 and 22.With 98% confidence, the mean width of all widgets is between 13.5 and 22.The mean width of all widgets is between 13.5 and 22, 98% of the time. We know this is true because the mean of our sample is between 13.5 and 22.

In which of the following scenarios can we calculate a confidence interval for the population mean? Check all that apply. A random sample of 60 cell phone calls is selected and the mean length of calls is determined to be 3.25 minutes with a standard deviation of 4.2 minutes. A random sample of 15 women athletes is selected and their mean weight is determined to be 136 pounds. Female athlete weights are known to be normally distributed with a population standard deviation of 20 pounds. A random sample of 14 cell phone calls is selected and the mean length of calls is determined to be 3.25 minutes with a standard deviation of 4.2 minutes. A random sample of 35 women athletes is selected and their mean weight is determined to be 136 pounds. Female athlete weights are known to be normally distributed with a population standard deviation of 20 pounds.

A simple random sample of seven (7) students is selected, and the students are asked how much time they spent studying for their University subjects (combined) outside class times. From past experience, it is known that these times (in hours) are distributed normally.The times (in hours) for the sample of students are as follows:2.3 7.2 4.5 12.5 6.6 2.5 5.5Based on these results, a confidence interval estimate for the population mean is found to be 5.9 ± 2.6.The level of confidence the researcher has used is closest to:-Group of answer choices95%90%97.5%99%