Question

For questions 13-16: Light exposure in mice Studies show that night-time light exposure is hamful to human health. A recent 6-week study randomly assigned lab mice to one of three conditions: LD (Group 1) had a standard light/dark cycle cach 24-hour period; (Group 2) LL had bright light all the time, and (Group 3) DM had dim light when there nomally would have been darkness. The rescarchers hoped to investigate how light exposure interacts with eating and sleeping cycles and whether it has an effect on weight gain. Among the variables recorded was the amount of body mass gained (g) by cach mouse over the 6-week period. Below are the results of the study. Sample size Mean Standard Deviation Group 7.859 3.009 1: LL 10 5.926 2: LD 1.899 2: DM 1,010 2.624 13. The researchers behind the study wish to conduct an ANOVA procedure to assess whether they can conclude the mean gain in body mass among the three groups of mice is significantly different. Which of the following is the appropriate set of hypotheses to test? Choose one. A) Hoi = B) H -i vs Hi At least one , is different from others C) Hai - D) None of these is corect. Hais vs Hai At least one , is different from others vs 14. Complete the ANOVA table (see the answer sheet) by filling in the blank cells 15. Compute the p-value associated with the F-test statistic in (14) 16. Use the results of your ANOVA procedure in (14) to select the appropriate conclusion regarding the null hypothesis for this research scenario. A) Reject Ho. We have sufficient evidence to say at least one of the three treatments corresponds to a mean weight gain (g) different than the others. The observed differences are not due to chance B) Reject Ho We have insufficient evidence to say at least one of the three treatments corresponds to a mean weight gain (g) different than the others. The observed differences are due to chance. C) Fail to reject Ho. We have insufficient evidence to say at least one of the three treatments corresponds to a mean weight gain (g) different than the others. The observed differences are due to chance. D) Fail to reject He. We have sufficient evidence to say at least one of the three treatments corresponds to a mean weight gain (g) different than the others. The observed differences are not due to chance.

Answer 1

be _ 13) Hypotteaes Mi bs difaent othens Atteat dne VS from n2 78.59 Tio 47 408 &X S926 X-2 T20 99.09 9X11-010 Tio 2 225 088 = Too 2 Again 2 + 70&.1796 Smdlakey 126 n2 2 369.7894 2 1152.1493. a22 30 183 Jhen 30 Tzo t Ti 1989.5595 10 Tr 1876.97. A gainConneetion factar -186-46子 2230.9183 Total Ss 2 54 4513

Arain ss Ru ton 1489.ST9S -t&t6 467 el13.0425 PPOro 35S TSS hun 3ll 241 3588

ANOVA Table Deebion SS Stunces of caniatin MS Cainlaled 56.54625 5.6228 3402Rejection Scbo.ellと SSE 041.3588 n-k 10-0566 tnr Sl 354.4512 Tolal 1-4

Agade velue P(F sbsenuad F) - P(PYS 6228 rangha eject Hence 4 at St elot Can hinfeanee Appropriat Cmelusion tlk 16 Rejeet to We hane stficdunteidenee to say alleatt ono st the thae treatouenl termrep ond weight gainf)difenent than the mean Otheus.he obsenve d difenenees chanee ae nof due t