1. Perform a linear regression for the accompanying John Deere tractor horsepower versus price data.
Images Horsepower Price
26 13600
48 19300
95 46300
105 60315
255 168900
450 200100
1. Determine the slope m

2. For the data above, determine the y-intercept

3. Determine the correlation coefficient r =

4. Is the correlation positive, negative, or neutral?

5. Is the correlation none, low, moderate, high, or perfect?

6. Determine the coefficient of determination

7. Based on the equation of the best fit line, what would be the predicted price for a 55 horsepower tractor?

8. Based on the equation of the best fit line, what would be the projected horsepower of a \$100,000 dollar tractor?

2. John Deere produces tractors in the 4000 and 5000 series with the following horsepowers:

20, 20, 32, 32, 35, 39, 40, 43, 43, 45, 45, 48, 48, 55, 55, 55, 65, 65, 65, 75, 75, 75

1. Find the sample size n: ______

2. Find the minimum: ______

3. Find the maximum: ______

4. Find the range: ______

5. Find the median: ______

6. Find the mode: ______

7. Find the sample mean : ______
8. Find the sample standard deviation sx: ______

9. Find the sample coefficient of variation CV:______

10. If this data is to be divided into five bins (classes, intervals) what is the width of a single bin? ________

11. Determine the frequency and calculate the relative frequency using five bins (classes, intervals). Record your results in the table provided.
Bins ( Classes or Intervals) Frequency Relative Frequency
_______ _______ _______
_______ _______ _______
_______ _______ _______
_______ _______ _______
_______ _______ _______

Sum:

_______________ _______________
12. Sketch a relative frequency histogram of the data on the back, labeling your horizontal axis and vertical axis as appropriate.

13. What is the shape of the distribution? ______________

14. What is the probability of a tractor having between 20 and 31 horsepower?

15. What is the probability of a tractor having between either 20 and 31 horsepower or 32 and 42 horsepower.

Statistic or Parameter Symbol Equations Excel
Square root =SQRT(number)
Sample mean Sx/n =AVERAGE(data)
Sample standard deviation sx =STDEV(data)
Sample Coefficient of Variation CV 100(sx/) =100*STDEV(data)/AVERAGE(data)
Slope b =SLOPE(y data, x data)
Intercept a =INTERCEPT(y data, x data)
Correlation r =CORREL(y data, x data)
Coefficient of Determination =(CORREL(y data, x data))^2