MS 150 Statistics quiz 04 fall 2007 • Name:

Half-marathon regression

INS marasong
time/min (x)dist/km (y)

Linear regression: On the 21st of July I completed the INS "marasong" half marathon. As I ran I tracked my time in minutes (min) and distance in kilometers (km) using a GPS. The data is given in the table above.

  1. ______________ Does the relationship between time and distance appear to be linear, non-linear, or random?
  2. ______________ Determine the slope of the linear regression (best fit line) for the data.
  3. ______________ Determine the y-intercept of the linear regression for the data.
  4. ______________ Determine the correlation coefficient r.
  5. ______________ Is the correlation positive or negative?
  6. ______________ Is the correlation none, weak, moderate, strong, or perfect?
  7. ______________ Determine the coefficient of determination.
  8. ______________ What percent in the variation in time "explains" the variation in distance?
  9. ______________ What would be the predicted distance after 45 minutes of running?
  10. ______________ What would be the predicted time for me to reach the finish line at Spanish wall at 20.3 kilometers?

  1. ______________ What is the probability of rolling a six on a twelve sided die numbered from one to twelve?
  2. ______________ What is the probability of rolling a three or a multiple of three on a fifteen sided die numbered one to fifteen?
  3. ________________________ Can a die be one-sided? What shape would a one-sided die be?
  4. What are the three ways of determining a probability?