Question

How to do with TI-83 Plus?

In class we examined the linear relationship between shoe size and height for females. When looking at the male data, the following statistics were computed. For shoe size, the sample mean was 11.4 and the sample standard deviation was 1.42. For height, the sample mean was 71.1 and the sample standard deviation was 3. The sample correlation between shoe size and height was found to be r = 0.65. Find the regression equation for predicting height from shoe size, and use it to compute predicted values of height.

Compute the intercept of the regression line. Round your answer to 3 decimal places.

Answer 1

Solution:

Given:

We use TI 83 or TI 84 if we have sample data values, but we are given sample statistic. Thus we can not use TI 83 to find regression equation, We will use following steps to find intercept and slope.

For shoe size,

the sample mean = = 11.4 and

the sample standard deviation = s_x = 1.42.

For height,

the sample mean = = 71.1 and

the sample standard deviation = s_y = 3.

The sample correlation between shoe size and height was found to be r = 0.65.

Find the regression equation for predicting height from shoe size, and use it to compute predicted values of height.

and intercept is:

Thus  the intercept of the regression line is:

Thus the slope of the regression line is:

Thus he regression equation for predicting height from shoe size, and use it to compute predicted values of height is: