A study examined the effect of protein consumption on weight gain in rats. Investigators obtained 14 female rats and randomly assigned 7 of them to a low-protein diet and the other 7 in a high-protein diet. After 60 days, the weight gained by each rat was recorded (in grams). Here are the summary findings, displayed as "mean (standard deviation)":
$$\begin{array}{l}
\begin{array} { l l }
\text { Low-Protein Diet}&\text { High-Protein Diet}\
101.3(20.6)&127.5(21.1)
\end{array}
\end{array}$$ Which of the following statements would lead us to believe that the t procedures were NOT safe to use here?

Question

A study examined the effect of protein consumption on weight gain in rats. Investigators obtained 14 female rats and randomly assigned 7 of them to a low-protein diet and the other 7 in a high-protein diet. After 60 days, the weight gained by each rat was recorded (in grams). Here are the summary findings, displayed as "mean (standard deviation)":
$$\begin{array}{l}
\begin{array} { l  l  } 
\text { Low-Protein Diet}&\text { High-Protein Diet}\
101.3(20.6)&127.5(21.1)
\end{array}
\end{array}$$ Which of the following statements would lead us to believe that the t procedures were NOT safe to use here?

Quizplus · Accepted Answer

The t procedures assume that the data are approximately normally distributed. If the distributions were skewed or had outliers, this assumption would be violated, making the t procedures potentially unsafe to use.