Question

College Algebra

Linear Regression Analysis

Please complete parts a, b, c, d and e. Use your graphing calculator to complete all parts. You may record your answers on a word document.

1. The table gives the age and systolic blood pressure for a sample of 12 randomly selected healthy adults.

Age	Systolic Blood pressure (mmHg)
17	110
21	118
27	121
33	122
35	118
38	124
43	125
51	130
58	132
60	138
64	134
70	142

a) Use a graphing utility to create a scatter plot for the data. Using the age as the

independent variable x and the Systolic Blood pressure as the dependent variable y.

Do the data appear to be linear?

**If when you hit GRAPH and you do not see anything change the window. Hit the window

button and choose option 9. Now do you see the graph?

b) Use the regression feature of a graphing utility to find a linear model for predicting

Systolic Blood pressure given age. Write below the linear equation you found using

your calculator. Include the correlation coefficient.

c) What does the correlation coefficient tell us about the data and the linear equation?

d) Use the linear model from part (b) to approximate Systolic Blood pressure for a

healthy 55 year old and healthy 30 year old.

Systolic Blood pressure for a 55 year old:

Systolic Blood pressure for a 30 year old:

e) Describe the trend you see in the data. How well does the function from part b fit

the data?

Answer 1

a) Use a graphing utility to create a scatter plot for the data. Using the age as the

independent variable x and the Systolic Blood pressure as the dependent variable y.

Do the data appear to be linear?

Yes, the data set is linear.

**If when you hit GRAPH and you do not see anything change the window. Hit the window

button and choose option 9. Now do you see the graph?

b) Use the regression feature of a graphing utility to find a linear model for predicting

Systolic Blood pressure given age. Write below the linear equation you found using

your calculator. Include the correlation coefficient.

y= 104.170+0.511x

Correlation Coefficient= 0.961

c) What does the correlation coefficient tell us about the data and the linear equation?

The correlation coefficient tells us about the relationship between the dependent variable (Systolic blood pressure) and the independent variable (Age). There is a strong positive relationship exists.

d) Use the linear model from part (b) to approximate Systolic Blood pressure for a

Systolic Blood pressure for a 55 year old: 132.2507

Systolic Blood pressure for a 30 year old: 119.4870

e) Describe the trend you see in the data. How well does the function from part b fit

the data?

There is an upward trend for this data. The function is good fit of the data.