QuestionSuppose that you run a correlation and find the correlation coefficient is 0.325 and the regression equation is . The centroid of your data was .
If the critical value is .632 , use the appropriate method to predict the value when is 3.9
Studdy Solution
STEP 1
What is this asking? Given a regression equation, correlation coefficient, critical value, and centroid, predict the *y*-value for a specific *x*-value. Watch out! Don't forget to consider the critical value when deciding whether to use the regression equation or the mean *y*-value from the centroid for prediction!
STEP 2
1. Compare the correlation coefficient and the critical value.
2. Predict the *y*-value.
STEP 3
The absolute value of the correlation coefficient is .
This tells us the strength of the linear relationship between *x* and *y*.
STEP 4
We're given a critical value of .
Since is less than , the correlation is *not* statistically significant.
This means we shouldn't use the regression equation for prediction!
STEP 5
Since the correlation isn't significant, the best prediction for any *x*-value is simply the average *y*-value, which is given by the *y*-coordinate of the centroid.
Our centroid is , so the mean *y*-value is **.
STEP 6
Therefore, when , our predicted *y*-value is .
STEP 7
The predicted *y*-value when is .
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