Question

Suppose that the amount of time INTI International University students spend in the library
per week is normally distributed. A sample of 6 students is selected at random, and the
sample mean computed as 13.83 hours with the standard deviation of 2.86 hour. Test at 1%
significance level whether the mean number of hours spend in the library per week is less
than 15 hours.

Answer 1

Solution :

This is the left tailed test,  

The null and alternative hypothesis is ,

H0 :   = 15

Ha : < 15

Test statistic = t =

= ( - ) / s / n

= (13.83 - 15 ) / 2.86 / 6

Test statistic = t = -1.00

degrees of freedom = n - 1 = 6 - 1 = 5

P(t < -1.00)

P-value = 0.1816

= 0.1

P-value >  

Fail to reject the null hypothesis .