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Sample Midterms 2

Geography 201a

Midterm Examination 2

November 5, 1997

Time: 50 minutes

 

Please answer each question as completely as you can. If you are unsure about what the question is asking, ASK the instructor or TA. Say what you mean and mean what you say. You are free to use the textbook or your notes. You may use a laptop computer or programmable calculator but not a cellular phone. Show all of your steps. Be sure to put only your student number on the front page and put your name on the back page! If you’re doing an inferential test, state the hypothesis.

There are 8 questions in this exam, so look on the back of the exam sheet as well as the front!

1. Give an example of a distribution (by this I mean an actual distribution not a hypothetical one) that would likely exhibit a large variance. Give an example of a distribution that would likely exhibit a small variance. (10 marks)

2. Give an example of a distribution where the median would be the best measure of central tendency. (10 marks)

3. What is the weighted centroid of the following points? (20 marks)

point (x,y) weight
1 1,1 2
2 3,4 1
3 5,5 3
4 3,3 1
5 4,1 2

4. The following population densities were determined along a transect from point 1 to point 11.

Point population density/sq km
1 100
2 90
3 80
4 85
5 60
6 50
7 65
8 35
9 30
10 45
11 20

 

Is this a random series? The median is 60. Assume "=.01. (15 marks)

5. What is the effect of increasing the dispersion in a data distribution on the likelihood of finding a significant difference between sample means using a t or z test? (5 marks)

6. For the following 2 samples determine if there is a statistically significant difference between them. Assume "=.05.

(25 marks)

Sample 1 Sample 2

X1 = 12.5 X2 = 15.0

s1 = 2.5 s2 = 2.4

n2 = 10 n2 =10

7. For the samples in problem 6, which has the larger dispersion in its sample? (10 marks)

8. How does sample size affect the likelihood of finding statistically significant differences in parametric statistics? (5 marks)

 

Geography 201a

Midterm Examination 2

November 11, 1998

Time: 50 minutes

Please answer each question as completely as you can. If you are unsure about what the question is asking, ASK the instructor or TA. Say what you mean and mean what you say. You are free to use the textbook or your notes. You may use a laptop computer or programmable calculator but not a cellular phone. Show all of your steps. Be sure to put only your student number on the front page and put your name on the back page! If you’re doing an inferential test, state the hypothesis and significance level.

There are 9 questions in this exam, so look on the back of the exam sheet as well as the front!

1. Give an example of a distribution (by this I mean an actual distribution not a hypothetical one) that would likely exhibit a large variance. Give an example of a distribution that would likely exhibit a small variance. (4 marks)

2. You are hired by the Institute in the Belief of Mythical Creatures to determine if the number of reports of leprechauns is consistent with the well known O’Hagan distribution. The following table gives the number of reports by county with the expected number from the O’Hagan distribution. Are the reports consistent with the O’Hagan distribution? (10 marks)
county number of reports expected number form distribution
A 12 21
B 64 30
C 10 5
D 23 20
E 11 5

3. Housing prices for 2 areas of London are reported. The following table gives the summary statistics for the two areas. Is the mean value of houses in area A statistically significantly different than those in area B? (12 marks)
area
A X bar = $79,000 F2= $5,000 n=10
B X bar = $81,500 F2 =$3,500 n=12

4. The following table shows by calendar quarter, the frequency counts of privately built houses completed in Cecilland and Seanania during 1967-1969. Does the seasonal pattern differ between countries. (30 marks)

Jan-March April-June July-Sept Oct-Dec
Cecilland 5682 5125 6098 7639
Seanania 6341 7360 7549 7227

5. Using the data from the previous table what is the 8 for the table? You need to determine the dependent and independent variables. (10 marks)

6. Determine the N coefficient and Cramer’s v for the table in problem 4. (4 marks)

7. The following population densities were determined along a transect from point 1 to point 11.

Point population density/sq km
1 250
2 225
3 200
4 212.5
5 150
6 125
7 162.5
8 87.5
9 75
10 112.5
11 50

Is this a random series? Assume "=.01. (20 marks)

8. What is the effect of increasing the dispersion in a data distribution on the likelihood of finding a significant difference between sample means using a t or z test? (5 marks)

9. How does sample size affect the likelihood of finding statistically significant differences in parametric statistics? (5 marks)