# Homework Chapter 6

Assignment:

Objective: Apply concepts Repeated Measures Design

1. A researcher is contemplating various ways to design their study examining the effects of irrigation on crop yield. The first possible design would be to take a sample of yields from plots with a standard irrigation system and compare them to the known yield from plots without irrigation in the same region. Another would be to sample irrigated and non-irrigation crop yields from various regions and compare them, ensuring the plots are matched on the variable of region. A final option would be to sample crop yields from the same plots first before and then after installation of a standard irrigation system and compare the yields prior to irrigation to those following irrigation. The research design that would best represent repeated measures design is ______________.

Objective: Apply techniques Conducting a Dependent Means t-test

1. A researcher predicts crop yields sampled from the same plots first before and then after installation of a standard irrigation system will differ. The scores for the research samples before and after irrigation are presented in the table below, in units (bushels per hectare; N=28). Conduct a hypothesis test of the researcher’s prediction with significance level .10. The populations should be defined as ______________.
 Plot Before irrigation After irrigation 1 163 208 2 131 198 3 160 208 4 183 198 5 168 186 6 135 177 7 179 173 8 143 203 9 161 203 10 154 192 11 162 186 12 163 185 13 166 176 14 181 184 15 132 199 16 149 197 17 169 199 18 148 202 19 169 188 20 158 200 21 143 201 22 150 191 23 178 194 24 147 185 25 170 202 26 171 178 27 169 212 28 180 180

1. For the research scenario described in problem 2, the hypotheses should be defined as ______________.
2. For the research scenario described in problem 2, the characteristics of the comparison distribution should be defined as ______________.
3. For the research scenario described in problem 2, the cutoff t score should be ______________.
4. For the research scenario described in problem 2, the calculated t-test result should be ______________.
5. For the research scenario described in problem 2, the hypothesis test decision should be ______________.
6. For the research scenario described in problem 2, the p-value associated with the t-test result is _____________.
7. For the research scenario described in problem 2, the conclusion as written in a published results section could be ______________.

Objective: Apply concepts Decision Tree

1. The dependent means t-test is appropriate to use when ______________.