Question 260293: Question:
2.Construct a scatter plot and include the regression line on the graph using excel for the given data. Determine whether there is a positive linear correlation, negative linear correlation, or no linear correlation. Complete the table and find the correlation coefficient r
In an area of the Midwest, records were kept on the relationship between the rainfall (in inches) and the yield of wheat (bushels per acre).
Rain fall, x 10.5 8.8 13.4 12.5 18.8 10.3 7.0 15.6 16.0
Yield, y 50.5 46.2 58.8 59.0 82.4 49.2 31.9 76.0 78.8
Scatter plot with regression line : I have already done this part
Type of correlation (positive linear correlation, negative linear correlation, or no linear correlation) Answer: positive linear correlation
Complete the table and find the correlation coefficient r rounded to 4 decimals.
n=9
r= 9(7187.77)-(112.9)(532.8)/square root 9 (1521.39)-112.92 square root 9 (33,836.58)-532.8*532.8=453.6/square root 9.46 square root 2.06=
Using the r calculated in problem 2c test the significance of the correlation coefficient using = 0.01 and the claim rho = 0. Use the 7-steps hypothesis test shown at the end of this project. (Note: Round the computed t to 3 decimals.)
1. H0 :
Ha :
2. this symbol means Specify the level of significance alpha =
3. Find the test statistic :t= r/square root 1-r^2/n-2
4. the critical value(s) t0.
5. Rejection region:
6. Decision:
7. Interpretation:
Find the test statistic :t= r/square root 1-r^2/n-2
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 2.Construct a scatter plot and include the regression line on the graph using excel for the given data. Determine whether there is a positive linear correlation, negative linear correlation, or no linear correlation. Complete the table and find the correlation coefficient r
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In an area of the Midwest, records were kept on the relationship between the rainfall (in inches) and the yield of wheat (bushels per acre).
Rain fall, x 10.5 8.8 13.4 12.5 18.8 10.3 7.0 15.6 16.0
Yield, y 50.5 46.2 58.8 59.0 82.4 49.2 31.9 76.0 78.8
Scatter plot with regression line : I have already done this part
Type of correlation (positive linear correlation, negative linear correlation, or no linear correlation)
Answer: positive linear correlation
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Complete the table and find the correlation coefficient r rounded to 4 decimals.
n=9
r= 9(7187.77)-(112.9)(532.8)/square root 9 (1521.39)-112.92 square root 9 (33,836.58)-532.8*532.8=453.6/square root 9.46 square root 2.06=
Note: I get r = 0.962 using a TI calculator.
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Using the r calculated in problem 2c test the significance of the correlation coefficient using alpha = 0.01 and the claim rho = 0. Use the 7-steps hypothesis test shown at the end of this project. (Note: Round the computed t to 3 decimals.)
1.
H0 :pho = 0 (that means no linear correlation)
Ha :pho is not 0
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2. this symbol means Specify the level of significance alpha = 1%
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3. Find the test statistic :t= r/square root 1-r^2/n-2
t = (1-0.962^2)/(9-2) = 0.01065
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4. the critical value(s) t0 = invT(0,005,8) = +/-3.3554
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5. Rejection region:
Reject Ho if |t|> 3.3554
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6. Decision:
The test Stat is not in the rejection interval so fail to reject Ho
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7. Interpretation: Reject the claim that there is no linear correlation.
The test supports the claim there is linear correlation at the 1% significance
level.
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Find the test statistic :t= r/square root 1-r^2/n-2
Comment: Whic formula are you using? this or the one above?
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Cheers,
Stan H.
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