Question

Question 1) In a random sample of 10 on-line statistics students, information was collected about their minutes studied and their chapter test scores. X is the minutes studied, and Y is the test score.

x : {20,30,45,60,80,90,45,120,90,70} y: {50,45,55,70,80,90,80,100,95,85}
Is this relationship positive, negative or no relation? Answer: (positive)

Using the data from question #1, what is the equation of the line of best fit? (For future reference: line of best fit, linear regression equation, and least-squares line are all the same thing y=ax+b). Round your answers to the nearest tenth. x : {20,30,45,60,80,90,45,120,90,70} y: {50,45,55,70,80,90,80,100,95,85}

Answer 1

First, arrange the data in a table for easy reference:

x y
20 50
30 45
45 55
60 70
80 80
90 90
45 80
120 100
90 95
70 85

Then, use the calculator to find the relationship of the two variables, x (minutes studied) and y (test scores)

The equation is

y = 0.56686x + 38.15