Answer :
To address these scenarios, let's identify the control group, the experimental group, the independent variable, and the dependent variable for each scenario. Here are the detailed steps for each scenario:
### Scenario 1:
Description:
A company wants to test a new dog food that is supposed to help overweight dogs lose weight. 50 dogs are chosen to get the new food, and 50 more continue their normal diets. After one month, the dogs are checked to see if they lost any weight.
Solution:
- Independent Variable: Type of food (new dog food vs. normal diet) — [tex]\(14\)[/tex]
- Dependent Variable: Weight loss in dogs — [tex]\(15\)[/tex]
- Experimental Group: 50 dogs receiving the new food — [tex]\(16\)[/tex]
- Control Group: 50 dogs with normal diet — [tex]\(17\)[/tex]
### Scenario 2:
Description:
A new sunscreen has been developed that is supposed to be more effective at preventing sunburn. 30 participants spray one arm with the new formula and the other arm with the leading formula. After 4 hours in the sun, their skin is evaluated for any redness.
Solution:
- Independent Variable: Type of sunscreen (new formula vs. leading formula) — [tex]\(18\)[/tex]
- Dependent Variable: Skin redness after sun exposure — [tex]\(19\)[/tex]
- Experimental Group: One arm of 30 participants sprayed with the new formula — [tex]\(20\)[/tex]
- Control Group: The other arm of 30 participants sprayed with the leading formula — [tex]\(21\)[/tex]
### Scenario 3:
Description:
A student wants to study the effect of sunlight on plant growth. In his experiment, 12 plants receive normal amounts of sunlight, but half of them are kept under bright sun lamps all night long. After 6 weeks, the plants' heights are measured.
Solution:
- Independent Variable: Amount of sunlight (normal sunlight vs. bright sun lamps all night) — [tex]\(22\)[/tex]
- Dependent Variable: Plant height — [tex]\(23\)[/tex]
- Experimental Group: 6 plants kept under bright sun lamps all night — [tex]\(24\)[/tex]
- Control Group: 6 plants receiving normal amounts of sunlight — [tex]\(25\)[/tex]
Thus, the given table should look like:
\begin{tabular}{|c|c|c|c|c|}
\hline Scenario & \begin{tabular}{l}Independent \\ Variable\end{tabular} & \begin{tabular}{l}Dependent \\ Variable\end{tabular} & \begin{tabular}{l}Experimental \\ Group\end{tabular} & \begin{tabular}{l}Control \\ Group\end{tabular} \\
\hline \begin{tabular}{l}A company wants to test a new dog food that \\is supposed to help overweight dogs lose \\weight. 50 dogs are chosen to get the new \\food, and 50 more continue their normal diets. \\After one month, the dogs are checked to \\see if they lost any weight.\end{tabular} & 14 & 15 & 16 & 17 \\
\hline \begin{tabular}{l}A new sunscreen has been developed that is \\supposed to be more effective at preventing \\sunburn. 30 participants spray one arm with \\the new formula and the other arm with the \\leading formula. After 4 hours in the \\sun, their skin is evaluated for any redness.\end{tabular} & 18 & 19 & 20 & 21 \\
\hline \begin{tabular}{l}A student wants to study the effect of sunlight \\on plant growth. In his experiment, 12 plants \\receive normal amounts of sunlight, but half of \\them are kept under bright sun lamps all night \\long. After 6 weeks, the plants' heights are \\measured.\end{tabular} & 22 & 23 & 24 & 25 \\
\hline
\end{tabular}
### Scenario 1:
Description:
A company wants to test a new dog food that is supposed to help overweight dogs lose weight. 50 dogs are chosen to get the new food, and 50 more continue their normal diets. After one month, the dogs are checked to see if they lost any weight.
Solution:
- Independent Variable: Type of food (new dog food vs. normal diet) — [tex]\(14\)[/tex]
- Dependent Variable: Weight loss in dogs — [tex]\(15\)[/tex]
- Experimental Group: 50 dogs receiving the new food — [tex]\(16\)[/tex]
- Control Group: 50 dogs with normal diet — [tex]\(17\)[/tex]
### Scenario 2:
Description:
A new sunscreen has been developed that is supposed to be more effective at preventing sunburn. 30 participants spray one arm with the new formula and the other arm with the leading formula. After 4 hours in the sun, their skin is evaluated for any redness.
Solution:
- Independent Variable: Type of sunscreen (new formula vs. leading formula) — [tex]\(18\)[/tex]
- Dependent Variable: Skin redness after sun exposure — [tex]\(19\)[/tex]
- Experimental Group: One arm of 30 participants sprayed with the new formula — [tex]\(20\)[/tex]
- Control Group: The other arm of 30 participants sprayed with the leading formula — [tex]\(21\)[/tex]
### Scenario 3:
Description:
A student wants to study the effect of sunlight on plant growth. In his experiment, 12 plants receive normal amounts of sunlight, but half of them are kept under bright sun lamps all night long. After 6 weeks, the plants' heights are measured.
Solution:
- Independent Variable: Amount of sunlight (normal sunlight vs. bright sun lamps all night) — [tex]\(22\)[/tex]
- Dependent Variable: Plant height — [tex]\(23\)[/tex]
- Experimental Group: 6 plants kept under bright sun lamps all night — [tex]\(24\)[/tex]
- Control Group: 6 plants receiving normal amounts of sunlight — [tex]\(25\)[/tex]
Thus, the given table should look like:
\begin{tabular}{|c|c|c|c|c|}
\hline Scenario & \begin{tabular}{l}Independent \\ Variable\end{tabular} & \begin{tabular}{l}Dependent \\ Variable\end{tabular} & \begin{tabular}{l}Experimental \\ Group\end{tabular} & \begin{tabular}{l}Control \\ Group\end{tabular} \\
\hline \begin{tabular}{l}A company wants to test a new dog food that \\is supposed to help overweight dogs lose \\weight. 50 dogs are chosen to get the new \\food, and 50 more continue their normal diets. \\After one month, the dogs are checked to \\see if they lost any weight.\end{tabular} & 14 & 15 & 16 & 17 \\
\hline \begin{tabular}{l}A new sunscreen has been developed that is \\supposed to be more effective at preventing \\sunburn. 30 participants spray one arm with \\the new formula and the other arm with the \\leading formula. After 4 hours in the \\sun, their skin is evaluated for any redness.\end{tabular} & 18 & 19 & 20 & 21 \\
\hline \begin{tabular}{l}A student wants to study the effect of sunlight \\on plant growth. In his experiment, 12 plants \\receive normal amounts of sunlight, but half of \\them are kept under bright sun lamps all night \\long. After 6 weeks, the plants' heights are \\measured.\end{tabular} & 22 & 23 & 24 & 25 \\
\hline
\end{tabular}
