Math 2201
Chapter 5 Test Review
Name____________
1.
Eight friends compare the number of photos that they have stored in their cell phones.
They have: 95, 85, 68, 100, 102, 75, 14, 85 photos on their phones.
A)
Determine the measures of central tendency for this data.
B)
Is the mean a good indicator to represent data set? Why or why not?
C)
What is the range of this data?
2.
Trying to decide on a birthday gift for his wife, Mr. Alexander asked his class about their
cell phones and how many different cell phones they have owned. The frequency table
shows their responses.
A)
B)
How many students answered his question?
Find the mean number of cell phones for the students in this class.
3.
The number of hours of television watched per week by a sample of 30 people is recorded
below.
8
21
13
6
17
22
18
12
26
16
29
15
18
3
22
32
24
16
19
21
27
18
11
16
12
25
12
17
20
26
A)
Choose a suitable bin for this set of data.
B)
Construct a frequency table.
C)
Draw a histogram and frequency polygon.
D)
How many of the people surveyed watched less than 5 hours of tv per week?
E)
What percent of the people surveyed 20 hours or more each week?
4.
Sally and Kimmy both work at The Food Centre. One evening after work the staff had a
competition that pitted the 2 girls against one another to see who could check out
groceries the fastest. Each girl was given 5 carts of groceries. Their times rounded to the
nearest minute are recorded below:
Sally
8
6
4
10
7
Kimmy
9
6
3
9
3
A)
Calculate the standard deviation for each worker.
B)
Who was the most consistent? Explain how you know?
C)
Who was the winner of the competition? Explain.
5.
The data below comes from a task in which the goal is to move a computer mouse to a
target on the screen as fast as possible. On 20 of the trials, the target was a small
rectangle; on the other 20, the target was a large rectangle. Time to reach the target was
recorded on each trial.
Compare the time it took to reach the small target to the time to reach the large target.
What conclusion can you make?
6.
The frequency polygons below shows the age distribution of people from 2 villages, one
in the UK and one in The Gambia
Using the information in the graph above, answer true or false to each statement below:
A)
There are 21 people between the age of 10-20 living in the UK village.
B)
Most people live longer in the UK village.
7.
From past records, it is found that the average life of a hair dryer used every day is about
6.5 years with a standard deviation of 1.5 years. If the data is normally distributed,
A)
construct the normal curve for the data
B)
what percentage of the hair dryers will last less than 3.5 years?
C)
what percent of the hair dryers will last longer than 8 years?
8.
For packaged chocolates, the mean mass is to be 40 g. The standard deviation is 1.5 g.
A)
If for a production run, 10 000 chocolates were produced, how many would be
within 1 standard deviation of the mean?
B)
How many chocolates would be rejected if the chocolates must have a mass
between 37 g and 43 g?
9.
The welds on an aircraft have a mean life of 500 flights with a standard deviation of 50
flights before weakening. If a particular aircraft flew only 480 flights before the welds
needed repair, determine the z-score.
10.
A line up for concert tickets has an average waiting time of 12 minutes with a standard
deviation of 4 minutes. What is the probability that you will wait in line for more than 20
minutes?
11.
On the World History public exam, the mean score was 72 and the standard deviation was
11. If Patricia’s z-score was 0.8,
A)
did she score a mark that was above or below the mean mark?
B)
what was her actual mark on the exam?
12.
Mr. Pinsent noticed that the number of hours students took to read the The Catcher in the
Rye formed a normal distribution curve with the average number of hours reported to be
10 and the standard deviation of 2.5.
A)
What percentage of the students would take less than 6 hours to read the novel?
B)
If Mr Pinsent has 120 Level 3 English students reading this book, about how
many would he expect to take less than 6 hours to read the novel?
C)
How many would take 14 hours to read it?
13.
A toothpaste commercial claims that 80% of dentists claim that this toothpaste is
effective in preventing cavities. It states the results are accurate 19 times out of 20 and
have a margin of error of
.
A)
What is the confidence interval?
B)
What is the confidence level? Explain what it means.
Answers:
1.
A)
B)
C)
mean = 78 Median = 85
mode = 85
No, because the mean is influenced by the outlier (14), it would not be a good
choice to describe this data.
range = 88
2.
3.
A)
A)
25 students
B)
mean = 2 cell phones
(32-3)/10 = 2.9 rounded up to 5
B)
C)
D)
1 person
E)
4.
A)
5.
6.
B)
Sally was more consistent because she had the lower standard deviation
C)
Kimmy has the fastes time (mean = 6 min) so she won the competition.
It appears that it generally took longer (more time) to reach the small target.
A)
False. 21 people between ages 10 and 20 live in the Gambian village
B)
True.
A)
7.
B)
2.5%
C)
16%
8.
9.
10.
11.
12.
13.
A)
B)
0.68 x 10 000 = 6800
0.95 x 10 000 = 9500
A)
B)
above the mean
A)
B)
C)
5.48%
0.0548 x 120 = 6.576 or 7 students
A)
B)
10 000 - 9500 = 500 would be rejected.
is her actual mark
0.0548 x 120 = 6.576 ( 7 students )
confidence interval: 75% - 85%
confidence level:
If a survey were conducted 100 times, then 95 times out of 100, the percent of
dentists who say the this brand of toothpaste is effective at fighting cavities would
range between 75% and 85%.