Researchers sampled a group of participants who completed a sleep intervention study and identified the 95% confidence interval of the mean hours of sleep as [8.15, 8.35]. For this example, the long-run probability that a confidence interval generated with this procedure will contain the true population mean is 95%, which is also known as1 pointthe confidence level. alpha (α).the Type I error rate.power.

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%

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of twenty three hours, what is the required sample size if the error should be less than three hours with a 95% level of confidence?

A study was conducted to estimate μ, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be σ = 3.6 hours. The 95% confidence interval for the mean, μ, is (7.7, 9.3).Which of the following will provide a more informative (i.e., narrower) confidence interval than the 95% confidence interval? Check all that apply. Using a sample of size 400 (instead of 81) Using a sample of size 36 (instead of 81) Using a different sample of size 81 Using a 90% level of confidence (instead of 95%) Using a 99% level of confidence (instead of 95%)

In a survey of 500 college students, 250 of them said they had stayed up late more than 10 times in the past year. A 95% confidence interval is constructed based on the percentage of college students in this sample who stay up late more than 10 times. What is the lower limit for the interval? (round the answer to two decimal places)

Which of the following is the width of the confidence interval for the population mean?