Question

A. The data below show the number of times a cricket chirps in a minute when the temperature is at a certain level in degrees Fahrenheit. Chips per minute 875 1050 1049 928 1199 850 Temperature(◦F) 75 87.3 80.2 78.2 89.4 74.7

1) Compute the correlation coefficient, r. Round 3 decimal places. In one sentence, explain the meaning of the correlation coefficient,r, in terms of the number of chirps and temperature. The correlation coefficient r = ------- blank fill out which means----- blank fill out.

2)Find the linear regression equation. (Least Squares Regression Line or Line of Best Fit).

y=

3)Find the best-predicted temperature ( ◦F) at a time when a cricket chirps at a rate of 1109 chirps per minute. Round decimal to one place.

Answer:

4) Determine the correlation of determination, r 2 , and write one statement of explanation.
Since r 2 = ? which means------ blank fill out

Answer 1

Solution:

1) Correlation coefficient r= 0.932

It means that there is strong positive correlation between temperature and cricket chirps.

Calculation:

2) regression equation is:

Y=36.376 + 0.0449X

3) for x= 1109 find Y

Y= 36.376 + 0.0449*1109

Y= 86.8

Calculation:

4) coefficient of determination R²=0.8679

Calculation: