Analysis of whether two categorical variables, X = course subject and Y = grade earned by a student was conducted. Researchers selected n 800 students for their study using m = 4 distinct courses and k = 6 grades, from A to F and W. They evaluated a x? test statistic for testing independence between X and Y equal to TS = 29.64 At the significance level a = 0.01, do researchers have sufficient evidence that X and Y are dependent? 1. Show critical value (or values) needed for this procedure 2. Formulate the rejection rule
Analysis of whether two categorical variables, X = course subject and Y = grade earned by a student was conducted. Researchers selected n 800 students for their study using m = 4 distinct courses and k = 6 grades, from A to F and W. They evaluated a x? test statistic for testing independence between X and Y equal to TS = 29.64 At the significance level a = 0.01, do researchers have sufficient evidence that X and Y are dependent? 1. Show critical value (or values) needed for this procedure 2. Formulate the rejection rule
MATLAB: An Introduction with Applications
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ISBN:9781119256830
Author:Amos Gilat
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Chapter1: Starting With Matlab
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![**Chi-Square Test for Independence: Analysis of Categorical Variables**
In a study analyzing the relationship between two categorical variables, $X =$ course subject and $Y =$ grade earned by a student, researchers selected $n = 800$ students. The study examined $m = 4$ distinct courses and $k = 6$ grades, from $A$ to $F$ and $W$. To test the independence between $X$ and $Y$, they calculated a chi-square ($\chi^2$) test statistic of:
\[ \text{TS} = 29.64 \]
The primary question is whether, at the significance level $\alpha = 0.01$, there is sufficient evidence to conclude that $X$ and $Y$ are dependent.
**Steps to Analyze the Test:**
1. **Critical Value:**
- Determine the critical value (or values) necessary for this procedure, based on degrees of freedom and the significance level.
2. **Rejection Rule:**
- Formulate the rejection rule for the test, using the critical value to decide if the null hypothesis should be rejected.
3. **Decision Making:**
- State your decision regarding the null hypothesis of independence, considering the calculated test statistic and the significance level $\alpha = 0.01$.
**Solution:**
To solve this problem, calculate the degrees of freedom for the chi-square test using the formula:
\[ \text{df} = (m - 1)(k - 1) \]
Next, find the critical value from the chi-square distribution table corresponding to $\alpha = 0.01$ and the calculated degrees of freedom. Compare the test statistic to this critical value to determine whether to reject the null hypothesis of independence.
This approach provides a step-by-step method to assess the dependency between course subjects and grades earned by students.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F5429ea10-b5c3-4b9c-8614-a48571d52f61%2F5e3b1af6-48b7-4872-a452-4ece9994e64d%2F1dfayr_processed.jpeg&w=3840&q=75)
Transcribed Image Text:**Chi-Square Test for Independence: Analysis of Categorical Variables**
In a study analyzing the relationship between two categorical variables, $X =$ course subject and $Y =$ grade earned by a student, researchers selected $n = 800$ students. The study examined $m = 4$ distinct courses and $k = 6$ grades, from $A$ to $F$ and $W$. To test the independence between $X$ and $Y$, they calculated a chi-square ($\chi^2$) test statistic of:
\[ \text{TS} = 29.64 \]
The primary question is whether, at the significance level $\alpha = 0.01$, there is sufficient evidence to conclude that $X$ and $Y$ are dependent.
**Steps to Analyze the Test:**
1. **Critical Value:**
- Determine the critical value (or values) necessary for this procedure, based on degrees of freedom and the significance level.
2. **Rejection Rule:**
- Formulate the rejection rule for the test, using the critical value to decide if the null hypothesis should be rejected.
3. **Decision Making:**
- State your decision regarding the null hypothesis of independence, considering the calculated test statistic and the significance level $\alpha = 0.01$.
**Solution:**
To solve this problem, calculate the degrees of freedom for the chi-square test using the formula:
\[ \text{df} = (m - 1)(k - 1) \]
Next, find the critical value from the chi-square distribution table corresponding to $\alpha = 0.01$ and the calculated degrees of freedom. Compare the test statistic to this critical value to determine whether to reject the null hypothesis of independence.
This approach provides a step-by-step method to assess the dependency between course subjects and grades earned by students.
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