What is the critical t value /2t α/2 for a 99% CI and a sample size of 50 would be?

What is the critical t value /2 t α/2for a 80% CI and a sample size of 70 would be?

Given the following statistics, n=35, =25.7 s =25.7 lbs, ¯=173.9 x¯=173.9 lbs. Estimate the true population mean using a 90% confidence interval. Interpret the results and round to the nearest tenth.

First, find the margin of error, E

We are 90% confidence that the true population mean falls in the interval ( ___lbs, lbs)

Given the following statistics, =100 =2.4 hg, ¯=15.7 x¯=15.7 hg. Estimate the true population mean using a 99% confidence interval. Interpret the results and round to the nearest tenth.

First, find the margin of error, E

We are 90% confidence that the true population mean falls in the interval

( hg, hg)

A new study from the University of Illinois finds that high engagement with mobile technology is linked to anxiety and depression in college-age students. The study was published in the journal Computers in Human Behavior. “There’s a long history of the public fearing new technologies as they are deployed in society,”’ said the U. of I. psychology professor, who conducted this study. “This fear of new technology happened with televisions, video games and most recently, smartphones, he said. With the growth of mobile technology and the accompanying concern about its mental health implications, the researchers wanted to explore the connection between these information and communication technologies and psychological well-being.”

We would like to determine the average number of hours that college-age students spend interacting with electronic media. We took a sample of 25 students. Here are the results of a survey of 25 students when asked: “How many hours do you spend consuming media every day (mobile usage, internet, TV, etc.)?”

4, 6, 9, 10, 12, 14, 4.5, 0, 7.5, 6, 9, 11, 13, 10, 7, 6, 11, 13, 2, 11, 10, 11, 14, 15, 9

Round answers to nearest tenth.

find x

find s

Make a 95% confidence interval for the true average number of hours college-aged students spend on media per day.

Make a 98% confidence interval for the true average number of hours college-aged students spend on media per day.

A study claims that spending more than 10 hours on media per day is linked to depression. Is it likely that the average number of hours per day is 10 hours?

Another study claims students who spend less than 4 hours on media per day report being happier. Is it likely that the average number of hours per day is less than 4 hours?