chapter 1

Chapter 8: Tests of Hypotheses Based on a Single Sample29.a. For n = 8, n – 1 = 7, and 1. 895s1.25Since = = . 442n8H o is not rejected.t , so H o is rejected at level .05 if ≥1. 895. 05,7=3.72 − 3.50, t == . 498.442t .; this does not exceed 1.895, soµ o− µ3.50 − 4.00d , and n = 8, so from table A.17, β ( 4.0) ≈ . 72b. = == . 40σ1.2530. n = 115, x = 11. 3 , s = 6. 431 Parameter of Interest: µ = true average dietary intake of zinc among males aged 65– 74 years.2 Null Hypothesis: H o : µ = 153 Alternative Hypothesis: H a : µ < 154z =x − µs /onx −15=s / n5 Rejection Region: No value of α was given, so select a reasonable level ofsignificance, such as α= .05.11.3 − µo6 z == −6.176.43 / 115z ≤ z or z ≤ −1. 6457 –6.17 < -1.645, so reject H o . The data does support the claim that average dailyintake of zinc for males aged 65 - 74 years falls below the recommended dailyallowance of 15 mg/day.α31. The hypotheses of interest are H o : µ = 7 vs H a : < 76.32 − 7H o should be rejected if t ≤ −t= 1. 397 . t = = −1.24not −1. 397. 1,8−µ , so a lower-tailed test is appropriate;1.65/≤ , H o (prior belief) is not rejected (contradicted) at level .01.9. Because -1.24 is246