Consider an experiment in which a pharmaceutical company is testing a new drug that they hope will lower cholesterol levels. They administer three treatments: A dose of the drug, a dose of a placebo, and a control group that receives neither drug nor placebo. after 24 hours they then measured the cholesterol levels and compared the values to baseline levels measured prior to treatment. The table below shows the results of the experiment.
$\begin{array}{|l|l|l|}\hline \text { Treatment } & \text { Chol. lower } & \begin{array}{l}\text { Chol. increased } \\\text { or the same }\end{array} \\\hline \text { Drug } & 64 & 36 \\\hline \text { Placebo } & 51 & 49 \\\hline \text { Control } & 48 & 52 \\\hline\end{array}$
-To determine whether there appears to be a statistically significant relationship between the treatment and changes in cholesterol level they would conduct a ?² analysis. When performing this analysis, which of the values below is closest to the ?² value they would compare the calculated value to in order to determine significance at the 5% level?

Question

Consider an experiment in which a pharmaceutical company is testing a new drug that they hope will lower cholesterol levels. They administer three treatments: A dose of the drug, a dose of a placebo, and a control group that receives neither drug nor placebo. after 24 hours they then measured the cholesterol levels and compared the values to baseline levels measured prior to treatment. The table below shows the results of the experiment.

\begin{array}{|l|l|l|}\hline \text { Treatment } & \text { Chol. lower } & \begin{array}{l}\text { Chol. increased } \\\text { or the same }\end{array} \\\hline \text { Drug } & 64 & 36 \\\hline \text { Placebo } & 51 & 49 \\\hline \text { Control } & 48 & 52 \\\hline\end{array}

-To determine whether there appears to be a statistically significant relationship between the treatment and changes in cholesterol level they would conduct a ?² analysis. When performing this analysis, which of the values below is closest to the ?² value they would compare the calculated value to in order to determine significance at the 5% level?

Quizplus · Accepted Answer

The chi-square test for independence uses degrees of freedom calculated as (rows - 1) * (columns - 1). Here, df = (3-1)*(2-1) = 2. The critical value for df=2 at the 5% significance level is 5.991.

Consider an Experiment in Which a Pharmaceutical Company Is Testing