MATH225N-10470 Week 4 Midterm Exam Week 1 – 4

QUESTION 1·1 POINT

To study whether there is a correlation between regular exercise and sleep, a researcher randomly selected 100 people who exercise regularly and 100 people who do not exercise regularly, and compared how many hours they sleep at night, on average.

Is the study observational or experimental? If it is an experiment, what is the controlled factor?

Select the correct answer below:

The study is an experiment. The controlled factor is the amount of sleep.

The study is an experiment. The controlled factor is the amount of exercise.

The study is an observational study.

The study is an experiment. The controlled factor is the survey.

 

QUESTION 2·1 POINT

A survey was given where students in a class were asked to state their birthplace. What is the level of measurement of the data?

Select the correct answer below:

nominal

ordinal

interval

ratio

QUESTION 3·1 POINT

Matthew wants to estimate the mean height of students attending his college. He records the heights of 235 randomly selected students attending the college. What is the population?

Select the correct answer below:

the mean height of the randomly selected students

the mean height of all students attending the college

the 235 randomly selected students

all the students attending the college

the heights of the randomly selected students

QUESTION 4·1 POINT

To study the sleeping habits of all band members in his school, Christopher obtains a list of the band members, divides the list into groups and randomly selects several groups to collect data. Which type of sampling is used?

Select the correct answer below:

Convenience sampling

Stratified sampling

Cluster sampling

Systematic sampling

QUESTION 5·1 POINT

In order to study the mean blood pressure of people in his town, Richard samples the population by dividing the residents by age and randomly selecting a proportionate number of residents from each age group. Which type of sampling is used?

Select the correct answer below:

Convenience sampling

Cluster sampling

Stratified sampling

Systematic sampling

QUESTION 6·1 POINT

A small startup company wishes to know how many hours, per week, that its employees spend commuting to and from work. The number of hours for each employee are shown below. Construct a frequency table for grouped data using four classes.

6, 5, 10, 15, 13, 3, 12, 3, 20, 10, 3, 12, 10, 13, 15, 8, 5, 7, 20, 3

Provide your answer below:

 

 

Lower Class Limit	Upper Class Limit	Frequency

 

QUESTION 7·1 POINT

The frequency table below shows the ages of the students in a math class.

Complete the Relative Frequency column of the table.

Provide your answer below:

Age	Frequency	Relative Frequency
17	8
18	3
19	10
20	12
21	11
22	6

 

QUESTION 8·1 POINT

A group of students were surveyed about the number of times they went to a movie theater last year. Their responses are summarized in the relative frequency table below.

What is the missing relative frequency?

Number of Movies	Relative Frequency
0−1	0.08
2−3	0.20
4−5	0.30
6−7	□
8−9	0.10
10 or more	0.08

 

Provide your answer below:

QUESTION 9·1 POINT

The values and relative frequencies for a set of data are shown below.

Complete the cumulative relative frequency table.

Provide your answer below:

Data Value	Relative Frequency	Cumulative Relative Frequency
1	0.39
2	0.05
3	0.30
4	0.26

 

QUESTION 10·1 POINT

A data set is summarized in the frequency table below. Using the table, determine the number of values less than or equal to 6.

 

Value	Frequency
2	3
3	4
4	6
5	3
6	2
7	3
8	4
9	5
10	4
11	4
12	2

Provide your answer below:

QUESTION 11·1 POINT

Describe the shape of the given histogram.

A histogram has a horizontal axis from 0 to 16 in increments of 2 and a vertical axis labeled Frequency from 0 to 10 in increments of 2. The histogram contains vertical bars of width 1 starting at the horizontal axis value 0. The heights of the bars are as follows, where the left horizontal axis label is listed first and the frequency is listed second: 0, 0; 1, 0; 2, 1; 3, 1; 4, 2; 5, 2; 6, 3; 7, 4; 8, 5; 9, 7; 10, 8; 11, 9; 12, 8; 13, 6; 14, 2; 15, 0.

Select the correct answer below:

uniform

unimodal and symmetric

unimodal and left-skewed

unimodal and right-skewed

bimodal

 

QUESTION 12·1 POINT

A set of data is summarized by the stem and leaf plot below.

Stem1234Leaf012223567788990012223457777888000011134466790000111222366889

Provide your answer below:

The value 19 appears  time(s) in the data set. The value 27 appears  time(s) in the data set. The value 41 appears  time(s) in the data set. The value 46 appears  time(s) in the data set.

 

QUESTION 13·1 POINT

Find the median for the following set of data:

35,42,38,37,38,41,47

Provide your answer below:

Median =

 

QUESTION 14·1 POINT

The following is a data set of the average weekly number of cups of coffee consumed by employees in an office. Find the mean and median and determine if the mean or median is the better measure of central tendency.

3,27,9,8,8,4,5,9,5,5,7,1,7,5,6,3

Select the correct answer below:

Mean = 7, Median = 5.5
The median is the better measure of central tendency.

Mean = 5.5, Median = 7
The median is the better measure of central tendency.

Mean = 5.5, Median = 7
The mean is the better measure of central tendency.

Mean = 7, Median = 5.5
The mean is the better measure of central tendency.

 

QUESTION 15·1 POINT

If the median of a data set is 16 and the mean is 10, which of the following is most likely?

Select the correct answer below:

The data are skewed to the left.

The data are skewed to the right.

The data are symmetrical.

 

QUESTION 16·1 POINT

Given the following box-and-whisker plot, decide if the data is skewed or symmetrical.

A horizontal box-and-whisker plot shares a vertical axis with the class A. A horizontal axis is labeled from 0 to 18 in increments of 2. The box-and-whisker plot class label A has the following five-number summary: 4, 6, 7, 9, and 16. All values are approximate. The part of the box at point 7 is represented with a dotted line.

Select the correct answer below:

The data are skewed to the left.

The data are skewed to the right.

The data are symmetric.

 

QUESTION 17·1 POINT

The following data values represent the daily amount spent by a family during a 5 day summer vacation.

Find the standard deviation of this dataset:

$120, $60, $250, $120, $200

• Round the final answer to one decimal place.

Provide your answer below:

$$std=

 

QUESTION 18·1 POINT

The following data set represents the ages of all six grandchildren in a family.

Find the variance for this data set of ages:

6, 3, 14, 11, 14, 6

• Round the final answer to one decimal place.

Provide your answer below:

$$variance=

 

QUESTION 19·1 POINT

Which of the data sets represented by the following histograms has the smallest standard deviation?

Select the correct answer below:

An untitled histogram has a horizontal axis labeled from 0 to 150 in increments of 50 and vertical axis labeled from 0 to 140 in increments of 20. The histogram contains vertical bars of width 4, starting at the horizontal axis value of 24. The approximate heights of the bars as follows, where the horizontal axis label is listed first and the approximate height is listed second: 60, 10; 62, 6; 64, 15; 68, 35; 70, 45; 76, 40; 80, 70; 84, 62; 88, 650; 92, 56; 96, 54; 100, 66; 104, 55; 108, 54; 112, 35; 116, 30; 120, 10; 120, 11; 124, 4; 128, 2.

A coordinate place has a horizontal axis labeled from 0 to 150 in increments of 50 and a vertical axis labeled from 0 to 140 in increments of 20. A series of bars are plotted such that their tips resemble a curve that rises and approaches a maximum approximately at left-parenthesis 90 comma 65 right-parenthesis, and then falls.

An untitled histogram has a horizontal axis labeled from 0 to 150 in increments of 50 and vertical axis labeled from 0 to 140 in increments of 20. The histogram contains vertical bars of width 4, starting at the horizontal axis value of 33. The approximate heights of the bars as follows, where the horizontal axis label is listed first and the approximate height is listed second: 33, 1; 36, 0; 39, 0; 42, 2; 45, 5; 48, 5; 51, 3; 54, 25; 57, 10; 60, 11; 63, 20; 66, 20; 69, 25; 71, 25; 74, 25; 77, 28; 80, 25; 83, 30; 86, 35; 89, 35; 92, 28; 95, 36; 98, 25; 101, 30; 104, 20; 107, 21; 110, 15; 113, 10; 116, 4; 119, 3; 121, 0, 124, 2; 127, 1; 130, 0; 133, 0; 136, 0; 139, 0; 141, 2.5.

An untitled histogram has a horizontal axis labeled from 0 to 150 in increments of 50 and vertical axis labeled from 0 to 140 in increments of 20. The histogram contains vertical bars of width 6, starting at the horizontal axis value of 75. The approximate heights of the bars as follows, where the horizontal axis label is listed first and the approximate height is listed second: 75, 6; 82, 18; 88, 70; 76, 115; 82, 150; 88, 103; 95, 70; 102, 20; 108, 8.

QUESTION 20·1 POINT

The five-number summary for a set of data is given below.

Min	Q1	Median	Q3	Max
40	69	72	79	86

Using the interquartile range, which of the following are outliers? Select all correct answers.

Select all that apply:

43

44

48

64

70

QUESTION 21·1 POINT

A deck of cards contains red cards numbered 1,2,3,4,5 and blue cards numbered 1,2,3,4. Let R be the event of drawing a red card, B be the event of drawing a blue card, E be the event of drawing an even-numbered card, and O be the event of drawing an odd card.

Drawing the red 2 is an example of which of the following events? Select all correct answers.

Select all that apply:

B AND O

B OR O

B′

E′

B OR E

R OR O

QUESTION 22·1 POINT

A deck of cards contains red cards numbered 1,2,3,4,5,6, blue cards numbered 1,2,3 and green cards numbered 1,2,3,4,5,6,7,8,9,10,11,12,13,14. If a single card is picked at random, what is the probability that the card is red?

• Give your answer as a fraction.

Provide your answer below:

FEEDBACK

Content attribution- Opens a dialog

QUESTION 23·1 POINT

Which of the pairs of events below is dependent?

Select the correct answer below:

drawing a 2 and drawing a 4 with replacement from a standard deck of cards

rolling two 4’s from two rolls of a standard die

drawing a heart and drawing another heart with replacement from a standard deck of cards

drawing a face card and then drawing a 3 without replacement from a standard deck of cards

QUESTION 24·1 POINT

Fill in the following contingency table and find the number of students who both go to the beach AND go to the mountains.

StudentsgotothebeachdonotgotothebeachTotalgotothemountains48donotgotothemountains21Total3695

Provide your answer below:

$$

QUESTION 25·1 POINT

The box-and-whisker plot shows the number of books read by history students during the last school year.

A box and whisker plot with minimum 4, first quartile 6, median 8, third quartile 10, and maximum 15

What is the range of the data?

Provide your answer below: