A survey of 570 working adults in the united states asked...

A survey of 570 working adults in the United States asked each participant how many hours they worked last week. The survey showed an average of 41.52 hours worked per week with a standard deviation of 14.82 hours. Is there enough evidence to show that Americans work more than 40 hours per week on average at the 0.01 significant level. is this a lwft tailed, right twilwd or two twiled test?

Transcript

00:01 All right, let's say we're given a data set and we're making an estimate that the average time that people work is 40.

00:10 And we take a sample size of 15 with these numbers, these 15 numbers that are listed on the whiteboard.

00:16 And we're trying to test if the true mean actually differs from 40.

00:21 So first, let's set up what our hypothesis test is.

00:24 So anytime we are testing if something is true, we always have a null hypothesis and we have an alternate hypothesis.

00:32 Our null hypothesis is that what we originally stated is true.

00:36 Our true population mean is equal to 40.

00:40 And because we are testing if the true mean is different from 40, our alternate is going to be not equal to 40.

00:48 So we don't care if it's less than or greater than, we just care that it's not equal.

00:53 Okay, so like now to like actually run our like hypothesis test, we actually want to use a t -test because we don't have any population standard deviation information.

01:05 So on our ti -84 calculator, you want to go to stat, go to tests, roll over to tests and click the second option, which is t -test.

01:24 So once you have that there, they're going to ask you for the input.

01:30 And you want to make sure that your input here is data because now we actually have the data of these 15 average hours per week values.

01:41 Under the mu not thing, this is the original mean that this committee says.

01:48 So that's going to be 40.

01:50 And then it's going to ask you for a list...