For Exercises 6.51 and 6.52, see pages 320321; for 6.53 to 6.55, see pages 323324; for 6.56 to 6.59, see pages 325326; for 6.60 to 6.62, see pages 328329; for 6.63 and 6.64, see page 331; and for 6.65 and 6.66, see page 332.

Question 6.63

6.63 Does the confidence interval include ?

The -value for a two-sided test of the null hypothesis is 0.037.

  1. Does the 95% confidence interval include the value 20? Explain.
  2. Does the 99% confidence interval include the value 20? Explain.

6.63

(a) No; because 0.037 is less than 0.05, we reject so that 20 falls outside the 95% confidence interval. (b) Yes; because 0.037 is greater than 0.01, we fail to reject so that 20 is inside the 99% confidence interval.