Question

> muncy = lm(hit_distance~launch_speed, data=muncy)

> summary(muncy)

Call:

lm(formula = hit_distance ~ launch_speed, data = muncy)

Residuals:

    Min      1Q Median      3Q     Max

-258.24 -105.23   23.29 116.06 174.73

Coefficients:

              Estimate Std. Error t value Pr(>|t|)   

(Intercept) -240.8429    36.6769 -6.567 1.46e-10 ***

launch_speed    4.8800     0.4022 12.134 < 2e-16 ***

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 122.4 on 438 degrees of freedom

Multiple R-squared: 0.2516, Adjusted R-squared: 0.2499

F-statistic: 147.2 on 1 and 438 DF, p-value: < 2.2e-16

a) Use R to find the equation of the regression line relating Y=hit distance and x=launch speed. Write the equation of the regression line.

b) Refer to the output in part a to explain why there is definitely a correlation between these quantities, but no one would ever attempt to predict hit distance from the launch speed variable only.

Answer 1