solutions7

solutions7 - Stat 665 (Spring 2011) Kaizar Solutions 7...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Stat 665 (Spring 2011) Kaizar Solutions 7 Exercises 40 points total 1. Nominal Regression (a) The prediction equations: log( ˆ μ 1 / ˆ μ 4 ) = 0 . 13 + 0 . 79 * A log( ˆ μ 2 / ˆ μ 4 ) = 0 . 71 + 0 . 18 * A log( ˆ μ 3 / ˆ μ 4 ) = 0 . 19 - 0 . 10 * A Where A = b 1 if alternating treatment 0 sequential treatment and μ 1 = probability of progressive disease μ 2 = probability of no change μ 3 = probability of partial remission μ 4 = probability of complete remission (b) Looking at the reported coeFcients, I estimate that the odds of progressive disease (logit = 0.79) or no change (logit = 0.18) vs. complete remission is larger for those who recieved alternating treatment. However, the odds of partial remission vs. complete remission (logit = -0.10) is smaller for those recieving alternating treatment. Although not always necessary, it is generally a good idea to examine the other relation- ships as well: log( ˆ μ 1 / ˆ μ 3 ) = 0 . 792 + 0 . 103 = 0 . 90 log( ˆ μ 2 / ˆ μ 3 ) = 0 . 176 + 0 . 103 = 0 . 28 log( ˆ μ 1 / ˆ μ 2 ) = 0 . 792 - 0 . 176 = 0 . 61 Looking at these comparisons, I estimate that the odds of progressive disease (logit = 0.90) or no change (logit = 0.28) vs. partial remission is greater for those receiving alternating treatment. ±inally, the odds of progressive disease vs. no change is also greater for those receiving alternating treatment (logit = 0.61). Thus, no matter how you look at it, alternating treatment seems to decrease the odds of a successful outcome. (c) probability of complete remission = e 1 e 0 . 792 + e 0 . 176 + e - 0 . 103 + e 1 = 0 . 387 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
(d) LRT = 16 . 47901 - 7 . 79364 = 8 . 685 χ 2 3 (8 . 685) = 0 . 0337 Since the p-value is so small, I conclude that the type of treatment does have a signiFcant association with the response. 2. (a) logit π 1 ) = - 1 . 22 + 0 . 57 A logit π 2 ) = 0 . 34 + 0 . 57 A logit π 3 ) = 1 . 38 + 0 . 57 A Where A = b 1 if alternating treatment 0 sequential treatment and π 1 = probability of progressive disease π 2 = probability of progressive disease or no change π 3 = probability of progressive disease or no change or partial remission
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

solutions7 - Stat 665 (Spring 2011) Kaizar Solutions 7...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online