Question

A study showed that in a certain month, the mean time spent per visit to Facebook was 19.5 minutes. Assume the standard deviation of the population is 8 minutes. Suppose that a simple random sample of 100 visits in that month has a sample mean of 21.14 minutes. A social scientist is interested in knowing whether the mean time of Facebook visits has increased. Perform the hypothesis test and compute the P-value.


Write down your P-value.
Round your answer to four decimal places (for example: 0.2305). Write only a number as your answer.

Answer 1

Given,

X_bar = 21.14

= 8

n = 100

1) Hypothesis :

H0 : =19.5

H1 : > 19.5

2) now calculate test statistic value

z = (x_bar - ​​​​​​) /(/n)

= (21.14 - 19.5)/(8/100)

z = 2.05

3) p value for Z test statistic is 0.0202

P value = 0.0202