A medical researcher is interested in determining if there is a relationship between adults over 50 who exercise regularly and low, moderate, and high blood pressure. A random sample of 236 adults over 50 is selected and the results are given below. Calculate the chi-square test statistic $\chi ^ { 2 }$ to test the claim that regular exercise and low, moderate, and high blood pressure are independent. Use $\alpha = 0.01$.
$\begin{array} { l | c c c }
\text { Blood Pressure } & \text { Low } & \text { Moderate } & \text { High } \
\hline \text { Reg. Exercise } & 35 & 62 & 25 \
\text { No Reg. Exercise } & 21 & 65 & 28
\end{array}$

A) 3.473
B) 16.183
C) 18.112
D) 6.003

Question

A medical researcher is interested in determining if there is a relationship between adults over 50 who exercise regularly and low, moderate, and high blood pressure. A random sample of 236 adults over 50 is selected and the results are given below. Calculate the chi-square test statistic $\chi ^ { 2 }$ to test the claim that regular exercise and low, moderate, and high blood pressure are independent. Use $\alpha = 0.01$.
$\begin{array} { l | c c c } 
\text { Blood Pressure } & \text { Low } & \text { Moderate } & \text { High } \
\hline \text { Reg. Exercise } & 35 & 62 & 25 \
\text { No Reg. Exercise } & 21 & 65 & 28
\end{array}$

A) 3.473
B) 16.183
C) 18.112
D) 6.003

Quizplus · Accepted Answer

The chi-square test statistic $\chi^2$ is calculated using the observed frequencies from the table and the expected frequencies, which are calculated based on the assumption that regular exercise and blood pressure levels are independent. The formula for the chi-square test statistic is $\chi^2 = \sum \frac{(O - E)^2}{E}$, where $O$ is the observed frequency and $E$ is the expected frequency for each cell in the table. After calculating the expected frequencies and applying the formula, the chi-square test statistic is found to be 3.473, which corresponds to choice A.

A Medical Researcher Is Interested in Determining If There Is χ2\chi ^ { 2 }χ2

A Medical Researcher Is Interested in Determining If There Is $\chi ^ { 2 }$