Questions: The following table compares the completion percentage and interception percentage of 5 NFL quarterbacks.
Completion Percentage 55 55.5 57 57.5 58.5
Interception Percentage 4 3.5 3 2.5 1.5
Calculate the correlation coefficient, r. Round your answer to three decimal places.
Transcript text: The following table compares the completion percentage and interception percentage of 5 NFL quarterbacks.
\begin{tabular}{|c|c|c|c|c|c|}
\hline Completion Percentage & 55 & 55.5 & 57 & 57.5 & 58.5 \\
\hline Interception Percentage & 4 & 3.5 & 3 & 2.5 & 1.5 \\
\hline
\end{tabular}
Calculate the correlation coefficient, $r$. Round your answer to three decimal places.
Solution
Solution Steps
Step 1: Calculate the Mean of Both Sets of Values
The mean of X, \(\bar{X}\), is 56.7. The mean of Y, \(\bar{Y}\), is 2.9.
Step 2: Compute the Deviations from the Mean
The deviations for each value in X and Y are calculated from their respective means.
Step 3: Calculate the Products of These Deviations
Each pair of deviations (from X and Y) is multiplied to calculate the products.
Step 4: Sum Up All the Products
The sum of all the products of deviations is -5.4.
Step 5: Calculate the Squared Deviations from the Mean
The squared deviations for each value in X and Y are calculated.
Step 6: Sum Up the Squared Deviations for Each Set
The sum of squared deviations for X is 8.300, and for Y is 3.7.
Step 7: Calculate the Correlation Coefficient
The correlation coefficient, \(r\), is calculated using the formula and is -0.974.
Final Answer:
The correlation coefficient, rounded to 3 decimal places, is -0.974.