Chapter 14 - Nonparametric Tests
1. A study investigated the level of caffeine in 16-ounce cups of Starbucks coffee. Coffee was purchased on 10 consecutive days from a single shop. The amount of caffeine in each cup is shown below:
564 498 259 303 305 307 295 328 356 290
a. Is there evidence to indicate the median is different from 300? Use α= .01.
b. Is there evidence to indicate the median exceeds 300? Use α= .01
c. Is there evidence to indicate the median is less than 300? Use α= .01
2. A real estate agent claims the median rent for a one-bedroom apartment in a city is $700 a
month. A sample of 25 rents shows that 17 of them have rents that exceed 700 and 8 are less than $700. Is there evidence the median is more than $700? Use Use α= .05.
3. A study of the treatment of pancreatitis patients compared length of hospital stays for medical treatment vs. surgical treatment.
Medical Surgical
3 3
3 4
5 4
6 5
7 6
8 6
10 6
12 9
13 10
11
Is there evidence that patients with the surgical treatment have a shorter stay. Use a=.05.
4. A clinical psychologist believes that deaf children have greater visual acuity than hearing children. Eye movement rates are taken on 10 deaf and 10 hearing children.
Deaf children 1.83 1.95 2.17 2.23 2.30 2.45 2.64 2.75 3.23 3.14
Hearing children 1.15 1.23 1.37 1.43 1.64 1.65 1.75 1.83 1.96 2.03
Is there evidence to support the psychologist’s claim? Use a=.05
(Larger scores indicate more visual acuity.)
5. A comparison of cholesterol levels before and after being on a diet was made on 8 individuals. Is there evidence to conclude the diet actually reduces the cholesterol level?
(a=. 05)
Person 1 2 3 4 5 6 7 8
Before 210 180 250 280 250 200 190 240
After 200 190 230 210 240 205 208 240
6. To compare 3 diets (A, B, C) in terms of weight loss, 5 people were put on each diet. The
weight losses are shown below. Is there evidence of a difference in the 3 diets?
(a=.05)
A B C
10 5 12
12 8 14
14 13 14
16 14 20
18 15 25
7. Plants and stress reduction : Ten students participated in a study to investigate the effect of plants on human stress levels. The data are given as finger temperatures for each of the students under 3 experimental conditions: plant, photo of a plant, no plant. Use a nonparametric procedure to determine if differences exist among the 3 conditions.Use a=.05.
Condition
Plant Plant photo No Plant
Student 1 91.4 93.5 96.6
2 94.9 96.6 90.5
3 97.0 95.8 95.5
4 93.7 96.2 96.7
5 96.0 96.6 93.5
6 96.7 95.5 94.8
7 95.2 94.6 95.7
8 96.0 97.2 96.2
9 95.6 94.8 96.0
10 95.6 92.6 96.6