CHAPTER 3 ASSIGNMENT
Describing Data: numerical Measures
Name
_____________________________________ Section
_______________ Score __________
Part I Select the correct answer and write the
appropriate letter in the space provided.
______
1. The
arithmetic mean is computed by
a. finding the value that
occurs most often.
b. finding the middle
observation and dividing by 2.
c. summing the values and
dividing by the number of values.
d. selecting the value in
the middle of the data set.
______
2. To
compute the arithmetic mean at least the
a. nominal level of
measurement is required.
b. ordinal level of
measurement is required.
c. interval level of
measurement is required.
d. ratio level of
measurement is required.
______
3. The
value that occurs most often in a set of data is called the
a. mean.
b. median.
c. geometric mean.
d. mode.
______
4. What
level of measurement is required to determine the mode?
a. at least nominal level
b. at least ordinal
c. at least interval level
d. ratio
______
5. For
a symmetric distribution
a. the mean is larger than
the median.
b. the mode is the largest
value.
c. the mean is smaller than
the median.
d. the mean and median are
equal.
______
6. Which
of the following is not true about the
arithmetic mean.
a. all the values are used
in its calculation
b. half of the observations
are always larger than the mean
c. it is influenced by a
large value
d. it is found by summing
all the values and dividing by the number of observations
______
7. In
a negatively skewed distribution
a. the mean is smaller than
the median.
b. the mean is larger than
the median.
c. the mean and median are
equal.
d. the median and the mode
are equal.
______ 8. What is the lowest level of measurement
required for the median?
a. nominal b. ordinal
c. interval d. ratio
______ 9. The
Dow Jones Industrial Average increased from 6110 at the end of the first
quarter in 1996 to 11,109 at the end of the first quarter in 2006. The annual
rate of increase is best described by the
a. geometric mean. b. weighted mean.
c. median. d. mode.
______ 10. What
is the shape of a frequency distribution with an arithmetic mean of 12,000
pounds, a median of 12,000 pounds, and a mode of 12,000 pounds?
a. flat b. symmetric
c. geometrically skewed d. positively skewed
______ 11. The mean deviation
a. is
the average of all the values.
b. is
the midpoint of the range.
c. is
the average of how far each value is from the median.
d. is
the average of how far each value is from the mean.
______ 12. The sum of the deviations from the mean is
always
a. equal
to the mean.
b. equal
to zero.
c. always
positive.
d. equal
to the median.
______ 13. The square of the standard deviation is
equal to
a. the
mean.
b. the
variance.
c. the
median.
d. the
mean deviation.
______ 14. What is the shape of a frequency
distribution with an arithmetic mean of 800 pounds, median of 758 pounds, and a
mode of 750 pounds?
a. negatively
skewed b. symmetric
c. geometrically
skewed d. positively skewed
______ 15. According to the Empirical Rule, about
what percent of the observations are within 2 standard deviations of the mean?
a. 50 b. 68
c. 99.7 d. 95
Part II Find the answers to
each of the following questions. Show
essential calculations.
16. A study conducted by the Toledo police at the
intersection of Byrne and Heatherdowns for the 7 to 9 AM drive time revealed
the following number of vehicles proceeded through the intersection after the
light changed. The information reported
below is for a sample of seven days during a six month period
6 12 7 12 8 4 5
a. Compute the range.
b. Compute the sample mean.
c. What is the median?
d. What is the mode?
e. Describe the skewness.
17. A shipment of packages to the Solomon
Company included 10 packages weighing 7.4 pounds, 12 weighing 8.2 pounds and 6
weighing 8.7 pounds. What value would you use as a typical amount for the
weight of a package?
18. The
mean daily attendance for eight large employers in Dade County is as follows:
95.7%,
95.3%, 95.5%, 95%, 94.7%, 93.7%,
93.8% 90.7%.
Find the average daily
attendance for the county.
19. From 1985 to 2006 the
net sales for the J.M. Smucker Company increased from $157 million to $687
million. Compute the mean annual percent
increase in net sales.
20. The numbers of orders placed online with
Jaysmart Electronics for the last 12
months were:
1136 1090
1273 1104 1180
1271 1211 887
1008 1300 1370
1263
a. Compute the range.
b. Compute the mean
deviation. c. Compute the standard
deviation.
21. The mean number of gallons of gasoline pumped
per customer at Ray’s Marathon Station is 9.5 gallons with a standard deviation
of 0.75 gallons. The median number of gallons pumped is 10.0 gallons. The
arithmetic mean amount of time spent by a customer in the station is 6.5
minutes with a standard deviation of 2.0 minutes.
a. According to Chebyshev’s
Theorem, what proportion (percent) of the customers spend between 3.30 minutes
and 9.70 minutes at the station? b. According to the
Empirical Rule, what proportion of the customers pump between 8.00 gallons and
11.00 gallons?
Hours spent Searching
|
Number of Unemployed
|
0 up to 10
|
3
|
10 up to 20
|
7
|
20 up to 30
|
15
|
30 up to 40
|
10
|
40 up to 50
|
5
|
TOTAL
|
40
|
22. The
Ohio Bureau of Employment gathered the following sample information on the
number of hours unemployed workers spent looking for work last week.
a. Determine the mean.
b. Determine the variance
and the standard deviation.
No comments:
Post a Comment