Stats

Chapter 11 Activity

Data for Problems 3-6 can be found as ‘Chapter 11 Activity’ in the Woodbury Math 21 StatCrunch group.

1) Two Proportion Test In a study of 1054 people who were 60 or older, New York City researchers found that 19 of the 459 women and 11 of the 595 men had lung cancer. At the 0.01 level of significance, test the claim that men over 60 are less likely to get lung cancer than women over 60.

2) Two Proportion Randomization Test A research company conducted a survey in which they asked, “How many tattoos do you currently have on your body?”

• Of the 60 males surveyed, 9 responded that they had at least one tattoo. • Of the 110 females surveyed, 14 responded that they had at least one tattoo.

Test the claim that the proportion of males that have a tattoo is the same as the proportion of females that have a tattoo, at the 0.05 level of significance.

3) Paired Difference Test In a study of a new wonder diet, a sample of 10 patients was taken. Here are there weights before and after.

Before 209 178 169 212 180 192 158 180 211 193 After 196 171 170 207 177 190 159 180 203 183 Test at the 0.01 level of significance the claim that this diet is effective, in other words, that the diet will reduce the weight of a person.

4) Wilcoxon Signed Ranks Test To test the belief that sons are taller than their fathers, a student randomly selects 13 fathers who have adult male children. She records the height of both the father and son in inches and obtains the following data. Test the claim that sons are taller than their fathers at the 0.05 level of significance.

Father 70.3 67.1 70.9 66.8 72.8 70.4 71.8 70.1 69.9 70.8 70.2 70.4 72.4 Son 74.1 69.2 66.9 69.2 68.9 70.2 70.4 69.3 77.8 72.3 69.2 68.6 73.9

5) Two Mean Test A high school instructor is curious to see the effect that an open-notes policy would have on tests. He allows one of his classes to use their notes on their test, while his other class takes the test without them. Here are the scores.

With Notes 86, 95, 92, 93, 83, 84, 91, 83, 87, 85, 84, 77, 79, 74, 78

Without Notes 70, 72, 77, 60, 81, 97, 84, 61, 78, 98, 68, 53, 69, 84, 91, 78

At the 0.05 level, test the claim that the use of notes produces a higher mean test score.

6) Mann Whitney Test A researcher plans soybeans in two types of plots: “No till” and “Chisel plowed”. The data represent the number of pods on a random sample of soybean plants for the two plot types.

Plot Type Pods No till 34 30 31 27 40 33 37 42 39 Chisel plowed 34 37 24 23 32 33 27 34 5 At the 0.05 level of significance, test the claim that the mean number of pods for “Chisel plowed” is less than “No till”.