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Statistical Inference about Slope

Answers

1. \(0.743±0.578\)

3. \(−0.610±0.633\)

5. \(T=1.732\), \(±t_{0.05}=±2.353\) , do not reject \(H_0\)

7. \(0.6±0.451\)

9. \(T=−4.481\), \(±t_{0.005}=±3.355\), reject \(H_0\)

11.  \(4.8±1.7 words\)

13. \(T=2.843\), \(±t_{0.05}=±1.860\), reject \(H_0\)

15.

  1. \(42.024±28.011\) thousand dollars,
  2. \(T=1.487\), \(t_{0.05}=1.943\) , do not reject \(H_0\);
  3. \(t_{0.10}=1.440\) , reject \(H_0\)

17. \(T=4.096\), \(±t_{0.05}=±1.771\), reject \(H_0\)

19. \(T=25.524\), \(±t_{0.0005}=±3.505\), reject \(H_0\)

21.
  1. \(2.550±0.127\) hundred psi,
  2. \(T=41.072\), \(±t_{0.005}=±3.674\), reject \(H_0\)

23.
  1. \((0.0014,0.0018)\)
  2. \(H_0: β_1=0.001\) vs. \(H_a: β_1 > 0.001\). Test Statistic: \(Z=6.1625\). Rejection Region: \([1.28,+∞)\).

    Decision: Reject \(H_0\).

25.
  1. \((101.789,131.4435)\)
  2. \(H_0: β_1=90\) vs. \(H_a: β_1 > 90\). Test Statistic: \(T=3.5938\). \(d.f.=58\). Rejection Region: \([1.296,+∞)\).

    Decision: Reject \(H_0\).