1 For each dataset write a model statement that addresses th

1) For each dataset write a model statement that addresses the question o note whether there are paired sampleslrepeated measures, blocks, or covariates sketch a graph of what the data might look like (it should put the variables on the right axes, and indicate the type of graph that is appropriate, although the actual pattern shown is not important) Data are provided only to illustrate the study design; no calculations are necessary A physician tests how five patients respond to each of three skin allergens by measuring skin redness after the allergen is applied. a) Do the allergens differ in their effects? Allergen PatientA 41 42 37 31 25 40 37 45 34 42 65 b) In a large dataset about birthweight and smoking, the education level of the mother has a significant effect on the baby\'s birthweight. However, mothers with less education might also be more likely to smoke, which also affects birthweight. Does education level still affect birthweight after smoking has been accounted for? ducation smoking birthweight HS past HS past HS less than HS past HS past HS HS 107 131 91 93 yes no yes yes yes yes yes no no no 127 104 125 148 132 116 past HS past HS HS

Solution

Sol)

A) WE USE ANOVA TWO WAY CLASSIFICATION

Ho: All the treatments are equal

Ho: All the blocks are equal

Level of significance:5%

Test Statistic:

F =(MSR)/MSE

From EXCEL

From above analysis

for Treatments:

F=1.726 and P =0.236 >0.05 , we accept the Null hypothesis.

For Blocks:

F=0.587 and P=0.5777>0.05, we accept the null hypothesis

Anova: Two-Factor Without Replication
SUMMARY	Count	Sum	Average	Variance
1	3	106	35.33333	80.33333
2	3	125	41.66667	20.33333
3	3	115	38.33333	37.33333
4	3	107	35.66667	32.33333
5	3	157	52.33333	220.3333
A	5	207	41.4	85.3
B	5	186	37.2	74.7
C	5	217	43.4	157.3
ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Rows	588	4	147	1.726365	0.236756	3.837853
Columns	100.1333	2	50.06667	0.587982	0.577768	4.45897
Error	681.2	8	85.15
Total	1369.333	14