Download Problem Set 1

Quiz 1
90.10.24
1. A recent issue of Fortune Magazine reported that the following companies
had lowest sales per employee among the Fortune 500 companies.
Company
Sales per
Employee
Sales Rank
Seagate
Technology
$42.2
285
SSMC
$42.19
414
Russell
$41.99
480
Maxxam
$40.88
485
Dibrell
Brother
$22.56
470
(a) How many elements are in the data set? Write down these elements.
(b) How many variables are in the data set? Write down these variables.
(c) How many observations are in the data set? Write down these observations.
(d) Which of the above variables are qualitative and which are quantitative?
2. Below you are given the grades of 20 students.
A
B
A
B
C
C
C
B
B
B
B
A
B
B
B
C
B
C
B
A
(a) Develop a frequency distribution and a relative frequency distribution for
this data.
(b) Construct a bar graph and a pie chart for this data.
3. Below you are given the scores of 10 college students who are enrolled in
statistics.
94
61
94
66
(a) Compute the mean
(b) The standard deviation.
(c) The coefficient of variation.
(d) The 30th percentile.
(e) The median.
(f) The mode.
94
68
75
85
84
78
(g) The interquartile range.
(h) Provide a five-number summary for the data.
(i) Show the box plot.
(j) Determine the outliers.
(k) Construct a frequency distribution, a cumulative frequency distribution and
a relative frequency distribution. Let the first class be 60-69.
(l) Based on the frequency table obtained in (k), compute the mean and variance
for the grouped data. Compare with the results in (a) and (b).
4.
(a) Consider a sample with a mean of 500 and a standard deviation of 100. What
are the z-scores for 520 and 280?
(b) Data that have a bell-shaped distribution have a mean of 30 and a standard
deviation of 5. Use both empirical rule and Chebyshev’s theorem to determine
the percentage of the data with range from 20 to 40.