chapter 1

Chapter 9: Inferences Based on Two Samples6.a. H o should be rejected if z ≥ 2. 33 . Sinceshould be rejected at level .01.z =( 18.12 −16.87)2.56 1.96+40 32= 3.53 ≥ 2.33, H o⎛⎜⎝1−0 ⎞⎟.3539 ⎠b. β ( 1 ) = Φ 2.33 − = Φ( − .50) = . 3085c.2.56 1.96 11.96+ == .1169 ⇒ = .0529 ⇒ n = 37.06240 nnn = 38.( 1.645 + 1.28), so used. Since n = 32 is not a large sample, it would no longer be appropriate to use the largesample test. A small sample t procedure should be used (section 9.2), and the appropriateconclusion would follow.7.1 Parameter of interest: µ 1− µ 2= the true difference of means for males andfemales on the Boredom Proneness Rating. Let1=µwomen’s average.2 H o : µ1− µ2= 03 H a : µ − µ 041 2>( x − y) − ∆ ( x − y )o −0z ==2 22 2s1s2s1s2++m n m nz ≥1.( 10.40 −9.26)− ∆oz == 1.83224.83 4.68+97 1485 RR: 6456µ men’s average and =7 Reject H o . The data indicates the Boredom Proneness Rating is higher for malesthan for females.2263