The Professor's Response

Hello professor,
I'm not getting question number 61 from the mixed review of chapter 11? I'm keep getting wrong answers.

  See the professor's answer below.

Professor McGukian

Hi,

This problem wants a confidence interval for the slope:

Step 1: get your data

n = 6

\scriptstyle\hat\beta = 0.842

SSxx = 619.333

S = 2.803

Step 2: get your t-critical value (remember, the degrees of freedom are n - 2 in this chapter)

ta/2, n - 2 = t0.025, 4 = 2.776

Step 3: Get your margin of error E = ta/2 * S / SqrRoot(SSxx) = 2.776 * 2.803 / SqrRoot(619.333) = 0.3126658

Step 4: ( \scriptstyle\hat\beta - E,  \scriptstyle\hat\beta + E) = ( 0.842 - 0.3126658, 0.842 - 0.3126658 ) = 0.529 to 1.155.

 

Hope that makes sense,

Professor McGuckian

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