Theme park guests visit world class parks to experience the thrills of roller coasters and attractions. Guests often spend 2 to 4 hours waiting to ride a roller coaster for only 2 minutes (duration). Data was gathered from a survey of roller coasters from around the world: speed ("S" - top speed in miles per hour), height ("H" - maximum height above ground level in feet), and length ("L" - total length of track). Engineers calculated the mean duration of the surveyed 110 rollercoasters and found the duration mean to be 123 seconds. The engineers want to predict the duration of a roller coaster based on the variables, S, L, and H. The multiple linear regression yielded the following parameter estimates: (Q1 - Q4)

1. Write the regression equation to predict duration based on S, H, and L.

2. When the overall top speed and length of track remain constant, the marginal change in

duration

3. Which parameter is not a significant predictor of duration?

4. Predict the duration of the new ride opening up in December 2020, if the maximum speed is 56 mph, maximum height above ground level in feet is 148 ft, and total length of track is 3221 ft.

variable DF Para. est. standard error t-value pr>t

intercept 1 24.640 3.062 8.0459 0.0385

s(mpg) 1 0.0109 0.1699 0.0642 0.0356

H(ft) 1 0.5132 0.0513 10.0039 0.4596

L(ft) 1 0.0165 0.0026 6.3462 0.0217