Question

home / study / math / statistics and probability / statistics and probability questions and answers / with all the fad diets advertised on tv, a researcher wanted to know if there was a significant ... Question: With all the fad diets advertised on TV, a researcher wanted to know if there was a significant d... Edit question With all the fad diets advertised on TV, a researcher wanted to know if there was a significant difference in weight loss depending on which new fad diet you were on. Over the course of 2 weeks, a total of 12 male volunteers who weighed the same and had similar lifestyles were broken up into 3 groups: Diet 1, Diet 2, and Diet 3. Conduct an ANOVA on the following table with alpha = 0.5 to determine if at least one of the diets has significantly different weight loss compared to the other two. Diet 1 -1 5 3 4 Diet 2-13 12 8 3 Diet 3-6 2 1 2 1. SS df MS F Between Within 85.5 Total 182 9. What is the conclusion based on your test statistic? Suppose researchers do an epidemiologic investigation of people entering a sexually transmitted disease clinic. Given the observed table below and α = 0.05, conduct a chi-square test for association to determine if there is an association between present diagnosis and prior episodes of urethritis. Previous Episodes of Urethritis Yes No Present Diagnosis Gonorrhea 32 23 Nongonococcal Urethritis 40 105 10. What is the alternative hypothesis? a. There is no association between present diagnosis and prior episodes of urethritis b. There is an association between present diagnosis and prior episodes of urethritis c. The presence of diagnosis is greater for those with a prior episodes of urethritis d. The presence of diagnosis is less for those with a prior episodes of urethritis 11. What is the critical value? a. 2.71 b. 3.84 c. 5.02 d. 6.63 12. What is the expected value of those with a present diagnosis of gonorrhea having a previous episode of urethritis? a. 81.69 b. 92.8 c. 19.8 d. 63.31 13. What is the expected value of those with a present diagnosis of gonorrhea not having a previous episode of urethritis? a. 35.2 b. 91.69 c. 118.31 d. 92.8

Answer 1

data

1	2	3
1	13	6
5	12	2
3	8	1
4	3	2

Anova: Single Factor
SUMMARY
Groups	Count	Sum	Average	Variance
1	4	13	3.25	2.916667
2	4	36	9	20.66667
3	4	11	2.75	4.916667
ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Between Groups	96.5	2	48.25	5.078947	0.033383	4.256495
Within Groups	85.5	9	9.5
Total	182	11

9)

TS = 5.0789

critical value = 4.256495

since TS > critical value

we reject the null hypothesis , because TS did fall in the rejection region

there is sufficient evidence that there us a significant difference