Circle the correct answer: (24 points)
1) If the distribution is right-skewed, then

A) The mean is more than the median.
B) The median is more than the mean.
C) The mean equals the median.
D) No enough information

2) If you select a simple random sample from each college in the university
and combined them in one sample, then this sample is called a ……

A) Simple random sample
B) Systematic sample
C) Stratified sample
D) Cluster sample

3) The mean (average) of the following data 3, 5, 3, b is 3. What is the value of b?
A) 5
B) 4
C) 2
D) 1
4) What is the mean and the median of the following data set: 12, 8, 15, 5, 20

``````  A) The mean is 12 and the median is 15
B) The mean 15 and the median is 12
C) The mean is 12 and the median is 12``````

D) The mean is 15 and the median is 15

``````    5) For the bell-shaped data, about 95% of the observations within…….
A) One standard deviation of the mean
B) Two standard deviations of the mean
C) Three standard deviations of the mean
D) None of the above``````

6) A measurement scale that rates the temperature is known as

A) Nominal
B) Ordinal
C) Interval
D) Ratio

7) Which of the following is a measure of variation?

A) The IQR
B) The median
C) The mean
D) The mode

8) You collected a data set on the nationality of all students at your university. The best graph to describe this data is a:

``````       A)    Histogram
B)    Box-plot
C)    Bar chart
D)    None of the above.``````

Problem 2:

Given that the prices of a TV-set are bell-shaped with mean \$950 and standard deviation \$150, answer the following (8 points)

a) About 99.7% of the prices are between \$ ……. and \$……..?

b) About 68% of the prices are between \$……….. and \$………. ?

Problem 3: (18 points)
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 20 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes).

118 124 108 116 99 120 139 118 119 121
80 130 125 100 105 132 120 128 89 95

Use Mega-stat to answer the following:

use megastat to construct a frequency table with 6 intervals. Paste the frequency table below and answer the following: (4 points)

a) What is the frequency of the first interval? (2 points)

b) What are the limits (lower limit and upper limit) of the second interval? (2 points)

c) What is the cumulative frequency of the fourth interval? (2 points)

d) Find the mean, and the standard deviation of the waiting time?
(4 points)

e) What is the shape of the histogram? (2 points)

f) What is the time such that 75% of the families wait below it?
(2 points)

``````                                                End of the assignment
``````

Sample Solution