Question

The following data give the number of hours 5 students spent studying and their corresponding grades on their midterm exams. Hours Studying 0 5 5 5 6 Midterm Grades 66 72 73 79 82 Table Step 3 of 5 : Calculate the estimated variance of slope, s2b1. Round your answer to three decimal places.

Answer 1

The problem is of regression analysis where the dependent variable is marks and the independent variable is hours.

We use minitab to do the calculation.

Steps : stat, regression, regression, fit regression model

if y=a+bx is the model, then b is the slope of the model. We are to find variance of b.

Here the model is

marks =65.26+2.175 hours.

So standard error coefficient of hours is 0.849 as given in the output. Hence estimated variance of the slope is 0.849^2 = 0.721