Question

1a. YouTube would like to test the hypothesis that the average length of an online video watched by a user is less than six minutes. A random sample of 40 people watch online videos that average 5.4 minutes in line. It is believed that the sample standard deviation for the length of online videos is 1.7 minutes. YouTube would like to set the level of significance equal to 0.05. The correct hypothesis statement for this hypothesis test would be

1b. Determine the level of significance

1c. Determine the test statistic

1d. Determine the critical value for the rejection region

Answer 1

Solution :

1b.

The level of significance () = 0.05

1c.

Test statistic (t) =

= ( - ) / s / n

= (5.4 - 6) / 1.7 / 40

Test statistic = -2.232

1d.

n = 40

Degrees of freedom = df = n - 1 = 40 - 1 = 39

= 0.05

t ,df = t0.05,39 = -1.685

The critical value for the rejection region is:

t < -1.685