Chapter 6.2, Problem 6.38E

(a)

To determine

To identify what are the explanatory variables and the response variables for this experiment.

Answer to Problem 6.38E

Explanatory variable is that each combination of temperature and time.

Response variable is the score of cake.

Explanation of Solution

The explanatory variable is that each combination of temperature and time.

The response variable is the score of cake.

(b)

To determine

To make a diagram to describe the treatments and find out how many treatments are there and how many cakes are needed.

Answer to Problem 6.38E

  $\text{there are 6 treatments}\text{.}$

  $\text{60 cakes}$ are needed.

Explanation of Solution

  $\begin{array}{l}{\text{Three temperatures: 300}}^0{\text{F,320}}^0\text{F},{340}^0\text{F}.\\ \text{Two times: 1 hour,1 hour 15 minutes}\text{.}\end{array}$

	300	320	340
1 hour	Treatment 1	Treatment 2	Treatment 3
1 hour 15 minutes	Treatment 4	Treatment 5	Treatment 6

  $\begin{array}{l}\text{We note that there are 6 treatments}\text{.}\\ \text{10 cakes such be baked for each treatment which is thus 60 cakes in total}\text{.}\\ \text{10}\times \text{6=60}\text{.}\end{array}$

(c)

To determine

To explain why it is a bad idea to bake ten cakes for one treatment at once then bake the ten cakes for the second experiment.

Explanation of Solution

When we are baking the cakes for the first treatment first then for the second treatment and so on. Then it is very likely that we will introduce lurking variables and the most likely lurking variable will be experience. The more cakes you make, the more experienced you become and the more likely that the cakes will have a better quality.