In dtkaplan/MultipleChoice: Support for Multiple Choice Questions in Shiny

if ( ! exists(".show_answers")) .show_answers <- TRUE

Using your general knowledge about the world, think about the relationship between these variables:

```{marginfigure echo = .show_answers} MODEL 1 ANSWER: Imagine that positive steepness means uphill, and negative steepness is downhill. As the hill gets steeper uphill, bicycle speed gets slower. So this model would be a line that slopes negatively.

MODEL 2 ANSWER: Increased fitness leads to higher speed, so the line of speed against fittness will slope upwards.

MODEL 3 ANSWER: Speed will go down with greater steepness (uphill) and speed will go up with greater fitness.

MODEL 4 ANSWER: Compared to Model 3, what's new here is the interaction term between steepness and fitness. Presumably, more fit people don't slow down as much when they encounter a hill, so the interaction should reduce the effect of steepness. ```

. speed of a bicyclist.

. steepness of the road, a quantitative variable measured by the grade (rise over run). 0 means flat, + means uphill, $-$ means downhill.

. fitness of the rider, a categorical variable with three levels: "unfit", "average", "athletic".

On a piece of paper, sketch out a graph of speed versus steepness for reasonable models of each of these forms:

• Model 1: speed ~ 1 + steepness
• Model 2: speed ~ 1 + fitness
• Model 3: speed ~ 1 + steepness+fitness
• Model 4: speed ~ 1 + steepness+fitness + steepness:`fitness``

dtkaplan/MultipleChoice documentation built on May 15, 2019, 4:58 p.m.