Question

A.The regression line for estimating time to do the job (in minutes) given duration of training (in hours) was found to be y=-1.702x + 57.85. what is the time to do the job for a training time of 8.2 hours?

b.test the hypothesis that increasing the duration of training significantly reduces the mean job time if r=-.78 test at 0.05

Answer 1

Time to do the job is y .

So, required time to do the job for training time 8.2 hrs is :

hrs .

To test hypothesis for correlation :

Alternative hypothesis : There is significant correlation .

Test statistic :  

So we need number of observation to test the hypothesis .

This can be done using the critical value approach too , there, the degrees of freedom will be (n-2) , n being the sample size