Fall 2001/Professor Yang
ASSIGNMENT #2Due Monday, September 19Problems:
1. The annual tractor output of a multinational firm in seven different countries was as follows (in thousands):
6, 8, 6, 9, 11, 5, 60
a) Graph the distribution, representing each output as a dot on the X-axis
b) What is the total output? What is the mean? The median? The mode? Mark these three centers on the graph.
c) For another firm operating in 10 countries, output (in thousands) had a mean of 7.8 per country, a median of 6.5, and a mode of 5.0. What is the total output?
2. In a test of the reliability of his machine, a technician repeatedly measured the viscosity of a specimen of crude oil. On each of three days, he took 50 measurements:
|
Viscosity |
FREQUENCY |
||
|
X |
Day 1 |
Day 2 |
Day 3 |
|
60 |
0 |
1 |
0 |
|
65 |
2 |
7 |
5 |
|
70 |
15 |
22 |
38 |
|
75 |
19 |
18 |
6 |
|
80 |
11 |
2 |
1 |
|
85 |
3 |
0 |
0 |
| N: 50 | N: 50 |
N: 50 |
a) Graph the 3 sets of data, side by side. Do you discern any trends from day to day?
b) For each of the 3 days, calculate the mean and standard deviation. Do these calculations show the same trends you observed in part a?
c) For the complete set of 150 observations, calculate the mean and standard deviation. How are they related to the means and standard deviations found in part b?
3. (Part B using SPSS) A researcher recorded the annual household income for a sample of 10 respondents. The responses as follows (reported in thousands of dollars):
($8,000) ($35,000) ($20,000) ($12,000) ($37,000) ($14,000) ($20,000) ($18,000) ($11,000)
a) Calculate the mean and standard deviation for this “household income” variable. Show all work.
b)
Next, confirm your by-hand calculation using SPSS. This
will require you to data-enter the ten cases in a blank data editor window.
Then run a frequency in SPSS requesting the two relevant descriptive statistics.
Append the relevant output table(s) in your homework.