|
Biology 401
- Biometry
|
Fall
2002 |
Sample Questions for Exam 4
Note - there are more questions in this sample than there
will be in the real exam
Test significance at alpha = 0.05 unless otherwise indicated.
- A psychologist is testing a group of 40 TV addicts with a word association
game, in which the subject responds to a word with the first word that pops
into his head. The psychologist wants to determine if these people are abnormal
in their responses by comparing the frequency of each response to those in
the "normal" population. Are these people a bit off-the-mark? (Data
also in Excel worksheet.)
Test word: "Blanket"
| Response |
Frequency in
general population (%) |
Number of test
subjects giving response |
| Bed |
55 |
10 |
| Warm |
25 |
6 |
| Comfort |
10 |
2 |
| Leroy |
0 |
13 |
| Tuberculosis |
0 |
7 |
| Other response |
10 |
2 |
- You want to test the hypothesis that the likelihood of retinal detachment
is related to eye color. You examine 100 people with detached retinas and
100 control subjects and obtain the counts shown below. Create a null hypothesis
and test it using an appropriate method.
| Detached retina: |
Blue eyes = 32 |
Brown eyes = 51 |
Other = 17 |
| Normal: |
Blue eyes = 37 |
Brown eyes = 40 |
Other = 23 |
- One hundred random people were surveyed and asked whether a) they smoked
and b) they coughed heavily in the morning. Is there a difference in the proportion
of coughers between smokers and non-smokers? Use any method desired to address
this question. (Data also in Excel worksheet.)
| |
Smoke? |
| Cough? |
Yes |
No |
| Yes |
18 |
7 |
| No |
12 |
63 |
- A study has just been completed examining the issue of mate choice as it
affects that bizarre creature, the science geek. In an experiment representing
a cross between Survivor and Club Med, 50 geeks and 100 normal people were
left on a tropical island, and a year later researchers assayed who was romantically
involved with whom. They found that, of the 75 couples, 40 were normal/normal,
20 were geek/geek, and 15 were normal/geek. Do geeks and normals appear to
choose their mates at random, or is there a bias in their selection?
- During an epidemic in a city, you are trying to determine whether new cases
of the disease are appearing at random, or instead tend to cluster together.
You have a map of the city showing how many cases have appeared in each square
block. What hypothesis might you want to test, and how would you go about
testing it?
- You are studying the pattern of depolarization in a neuron from the brain
of a banana slug. Over a two-hour period, you measure the number of depolarizations
per minute (data in Excel worksheet). Can you reject the hypothesis that the
timing of the depolarizations is random?
- A new stop-smoking product, the Oral Patch, is being tested for effectiveness
in keeping people from starting to smoke again while using the product. The
patch, which is placed over the user's mouth, is being compared to a more
traditional nicotine-laced skin patch. A "survival" table is created
for the 100 people tested for each product, showing how many individuals started
smoking or were lost each week. Using this data (in the Excel worksheet),
finishing constructing the suvival tables and then compare the effectiveness
of the two products.