Question

The ages (in years) of 10 infants and the number of hours each slept in a day
Age, x: 0.1, 0.2, 0.4, 0.7, 0.6, 0.9, 0.1, 0.2, 0.4, 0.9
Hours slept, y: 14.9, 14.5, 13.9, 14.1, 13.9, 13.7, 14.3, 13.9, 14.0, 14.1
Find the equation of the regression line. Then use the regression equation to predict the value of y for the given x, if meaningful. If it is not meaningful, explain why.
a. X-0.3years b. X=3.9years c. X=0.6years d. X=0.8years

Answer 1

If you need to show the work by hand, you can develop the regression equation in the following format:
predicted y = a + bx
...where a represents the y-intercept and b the slope.

To get to that point, here are some formulas to calculate along the way.

To find a:
a = (Ey/n) - b(Ex/n)

Note: E here means to add up or to find the total.

To find b:
b = SSxy/SSxx

To find SSxy:
SSxy = Exy - [(Ex)(Ey)]/n

To find SSxx:
SSxx = Ex^2 - [(Ex)(Ex)]/n

Once you have the equation, substitute the values for x and solve for predicted y.

I hope this will help get you started.

Answer 2

Solution