In-Class Assignment Ch 14 Example PDF

Preview

Summary

In-Class Assignment Ch 14 Example...

Description

In-Class Assignment Ch 14 Example Example 1:

Calculation: Step 1) In StatCrunch, click “Stat”  “Regression”  “Simple Linear”

In-Class Assignment Ch 14 Example Step 2) Select the correct x- and y- variables.

Step 3) Result

R-square (from statcrunch) = 0.0196 F-statistic (from statcrunch) = 0.04 F-critical value (calculated from Excel) =F.INV.RT(0.05,1,2) = 18.5128

In-Class Assignment Ch 14 Example Example 2:

Calculation: Step 1) In StatCrunch, click “Stat”  “Regression”  “Simple Linear”

In-Class Assignment Ch 14 Example Step 2) Select the correct x- and y- variables. Input the x-value and confidence level under “Prediction of Y”.

Step 3) Result

Confidence Interval for x = 5: (4.045, 6.193)

In-Class Assignment Ch 14 Example Example 3:

Calculation for Part A: Confidence interval formula: Y^hat ± t-critical*Syx*SQRT(h)

Step 1) find Y^hat Y^hat = 6+2x At x =5, Y^hat = 6+2*5 = 16

Step 2) find h h = (1/29) + ((5-8)^2)/29 = 0.34483

Step 3) find t-critical (where alpha = 0.1) t-critical = T.INV(0.05,27) = -1.70329

Step 4) find confidence interval Y^hat ± t-critical*Syx*SQRT(h) (16) + (-1.70329)*3.2*SQRT(0.34483) = 12.7993 = Lower bound (16) - (-1.70329)*3.2*SQRT(0.34483) = 19.2007 = Upper bound

In-Class Assignment Ch 14 Example Calculation for Part B: Prediction interval formula: Y^hat ± t-critical*Syx*SQRT(1+h)

Step 1) find Y^hat (same as Part A) Y^hat = 6+2x At x =5, Y^hat = 6+2*5 = 16

Step 2) find h (same as Part A) h = (1/29) + ((5-8)^2)/29 = 0.34483

Step 3) find t-critical (same as Part A) t-critical = T.INV(0.05,27) = -1.70329

Step 4) find prediction interval Y^hat ± t-critical*Syx*SQRT(1+h) (16) + (-1.70329)*3.2*SQRT(1+0.34483) = 9.6792 = Lower bound (16) - (-1.70329)*3.2*SQRT(1+0.34483) = 22.3208 = Upper bound...