Question

. The paired data consist of the temperature (in °F) on randomly chosen days and the amount a Rose plant grew (in millimeters).

Temp	Growth
65	81
83	93
61	76
72	89
50	65
91	87

STATDISK Results

Correlation Results: Correlation Coeff, r: 0.86615 Critical r:            ±0.81140 P-Value (two-tailed): 0.02568 Regression Results: Y= b0 + b1x: Y Intercept, b0:      40.27844 Slope, b1:            0.59083

1. Use the STATDISK results provided to construct the regression equation y=mx+b, where m is slope and b is the y-intercept . Round all values three decimal places.                           

2. Use the regression equation to predict the expected growth when the temperature is 75^o F. Round the value to one decimal place. Substitute 75 degrees in for x.

3. Find r2.

4. What does r2 tell us? (Use a complete sentence!)

Answer 1

Solution-a:

From regresssion equation

y=0.59083*x+40.27844

1. Use the regression equation to predict the expected growth when the temperature is 75o F. Round the value to one decimal place. Substitute 75 degrees in for x.

y=0.59083*x+40.27844

For c=75 we get

y=0.59083*75+40.27844

y= 84.59069

y=84.6

Predicted ]expected growth=84.6

1. Find r2.

r^2=r*r

= 0.86615* 0.86615

=0.7502158

1. What does r2 tell us? (Use a complete sentence!)

R sq=0.7502158

=0.7502158*100

=75.02%

75.02% variaition in growth is explained by temperature

explained avriance by model=75.02%

unexplained variance=100-75.02=24.98%