Question 1

As part of a large ongoing study on the treatment of women with breast cancer,the treatment time (in months)of eight patients whose lymph nodes were cancer-free is recorded.Treatment time is defined as the time from the moment the cancer treatment starts until the patient is declared cancer-free.  What is the mean treatment time for these eight women?
A)10.5 months
B)11.67 months
C)12.325 months
D)15 months

Accepted Answer

The answer of As part of a large ongoing study...

Question 2

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC.  What percentage of women completed at most their junior year?
A)5%
B)17%
C)67%
D)100%

Accepted Answer

To find the percentage of women who completed at most their junior year, we need to add up the percentages for the "Some college, no degree," "Associate's degree," and "Some high school" categories. This adds up to 17%. Therefore, the correct answer is B, 17%.

Question 3

A nationwide study was done to assess the programming proficiency of students taking a statistical programming class.The students were asked their proficiency in the statistical software SAS.The survey was sent to students at over 100 universities and 112 responses were received from 21 different universities.The results were published in the journal International Mathematical Forum in 2011.The results in the form of a pie chart are shown below.  From the pie chart,we can see that most students are _____.
A)not proficient at all
B)somewhat proficient
C)very proficient

Accepted Answer

The answer of A nationwide study was done to assess...

Question 4

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC.  How many males completed at least some graduate school?
A)5
B)2
C)3
D)60

Accepted Answer

From the bar graph, we can see that the number of males who completed at least some graduate school is represented by the section above the "Graduate School" label. This section is divided into 3 parts, each representing 5 males. Thus, the total number of males who completed at least some graduate school is 3 x 5 = 15. However, the question is asking for the number of males who completed at least some graduate school, not the number of sections representing this group. Therefore, the answer is 2 (since the section representing "Graduate School" itself is not included in the count).

Question 5

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC.  What percentage of men completed at most their freshman year?
A)1%
B)100%
C)0%
D)This cannot be determined from the information given.

Accepted Answer

The bar graph does not provide any information regarding the number of men who completed at most their freshman year. Therefore, it cannot be determined from the information given.

Question 6

On the first day of class,statistics professors ask each student to fill out a demographic questionnaire to learn information about their class.Which of the following variables is/are categorical?
A)Gender
B)Marital status
C)Highest education level of your mother (e.g. ,high school grad,college grad,etc. )
D)All of the above
E)None of the above

Accepted Answer

All of the variables listed are categorical. Gender and marital status have categories (male/female and married/single/divorced/widowed), while education level has categories as well (high school grad, college grad, etc.).

Question 7

Which of the following variables is quantitative?
A)The amount of time a student spends on the Internet in a week
B)The number of tenured professors at a large university
C)The number of hurricanes each year for the years 2000 to 2010
D)All of the above
E)None of the above

Accepted Answer

All the options (A, B, C) describe variables that can be measured in numerical terms, which defines them as quantitative.

Question 8

The median age of five people in a meeting is 30 years.One of the people,whose age is 50 years,leaves the room.What is the median age of the remaining four people in the room?
A)40 years
B)30 years
C)25 years
D)This cannot be determined from the information given.

Accepted Answer

The median age of the remaining four people cannot be determined with the information given because we do not know the ages of the other four individuals, only that the median of all five was 30 when the 50-year-old was included. Removing the 50-year-old could change the median in an unpredictable way without more specific age information for the remaining individuals.

Question 9

A nationwide study was done to assess the programming proficiency of students taking a statistical programming class.The students were asked their proficiency in the statistical software SAS.The survey was sent to students at over 100 universities and 112 responses were received from 21 different universities.The results were published in the journal International Mathematical Forum in 2011.The results in the form of a pie chart are shown below.  True or False.A bar graph would give the same information?

Accepted Answer

The answer of A nationwide study was done to assess...

Question 10

On the first day of class,statistics professors ask each student to fill out a demographic questionnaire to learn information about their class.Which of the following variables is/are quantitative?
A)Gender
B)Marital status
C)Highest education level of your mother (e.g. ,high school grad,college grad,etc. )
D)Household income

Accepted Answer

Household income is a quantitative variable because it is a numeric measurement.

Question 11

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC.  Approximately how many people are college graduates?
A)15
B)7
C)22
D)1

Accepted Answer

From the graph, we can see that 11 females and 11 males are college graduates, which makes a total of 22 people. Therefore, the answer is C.

Question 12

The World Malaria Report (2008)has information on the number of reported malaria cases from 2005 and 2006 for the 10 countries listed in West Africa.The data are presented in the table below.  If the number of malaria cases for Ghana were removed from this data set,what would happen to the mean of the entire data set for the year 2005?
A)The mean would not change.
B)The mean would change.
C)You cannot tell without doing the calculation.

Accepted Answer

Removing Ghana would decrease the total number of malaria cases in the dataset for 2005, which would decrease the sum of the cases and change the mean value.

Question 13

The Environmental Protection Agency records data on the fuel economy of many different makes of cars.Data on the mileage of 20 randomly selected cars are listed below.The values are ordered for convenience.  What is the median mileage for these 20 cars?
A)17.5 miles per gallon
B)19 miles per gallon
C)19.5 miles per gallon
D)20 miles per gallon

Accepted Answer

To find the median, we need to find the middle value when the data is ordered. Since we have 20 data points, the middle two values must be averaged to find the median.

When the data is ordered, the middle two values are 19 and 20.

(14, 15, 16, 17, 18, 18, 19, 19, 20, 20, 22, 23, 23, 24, 25, 26, 28, 30, 31, 31)

The average of 19 and 20 is 19.5, so the median mileage for these 20 cars is 19.5 miles per gallon. Therefore, the answer is C.

Question 14

The World Malaria Report (2008)has information on the number of reported malaria cases from 2005 and 2006 for the 10 countries listed in West Africa.The data are presented in the table below.  If the number of malaria cases for Sierra Leone were removed from this data set,what would happen to the mean of the entire data set for the year 2006?
A)The mean would not change.
B)The mean would change.
C)You cannot tell without doing the calculation.

Accepted Answer

Removing Sierra Leone from the data set would decrease the total number of cases for the year 2006. Therefore, the mean of the entire data set for 2006 would change.

Question 15

A consumer group surveyed the prices for cotton,extra-long twin bed sheet sets in five different department stores and reported the average price as $16.We visited four of the five stores and found the prices to be $12,$15,$17,and $22.Assuming that the consumer group is correct,what is the price of the item at the store that we did not visit?
A)$10
B)$14
C)$15
D)$17

Accepted Answer

The average price of the sheet sets in the five stores is $16, so the total price for all five stores is 5 * $16 = $80. The sum of the prices in the four stores visited is $12 + $15 + $17 + $22 = $66. Therefore, the price at the store not visited is $80 - $66 = $14.

Question 16

A researcher reports that,on average,the participants in his study lost 10.4 pounds after 2 months on his new diet.A friend of yours comments that she tried the diet for 2 months and lost no weight,so clearly the report must be a fraud.Which of the following statements is correct?
A)Your friend must not have followed the diet correctly because she did not lose weight.
B)Because your friend did not lose weight,the report must not be correct.
C)The report gives only the average.This does not imply that all participants in the study lost 10.4 pounds or even that all participants lost weight.Your friend's experience does not necessarily contradict the study results.
D)In order for the study to be correct,we must now add your friend's results to those of the study and recalculate the new average.

Accepted Answer

The report gives only the average weight loss, and it is possible that some participants did not lose weight or even gained weight. So, the fact that your friend did not lose weight does not necessarily mean that the report is fraudulent.

Question 17

A nationwide study was done to assess the programming proficiency of students taking a statistical programming class.The students were asked their proficiency in the statistical software SAS.The survey was sent to students at over 100 universities and 112 responses were received from 21 different universities.The results were published in the journal International Mathematical Forum in 2011.The results in the form of a pie chart are shown below.  It would have been better to display the data in a histogram.

Accepted Answer

A pie chart is appropriate for displaying the distribution of categorical data, such as the proportion of respondents who reported each level of proficiency in SAS. However, a histogram would be more appropriate for displaying the distribution of a numerical variable, such as the number of students who reported each level of proficiency.

Question 18

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC.  More men than women are college graduates.

Accepted Answer

The bar graph shows that there are more men than women in the category of "college graduate" (approximately 28 men compared to 18 women). Therefore, it is true that more men than women in this sample achieved a college education.

Question 19

According to the Bureau of Labor and Statistics in 2014,the average salary of all female workers is $37,596.The average salary of all male workers is $45,500.What must be true about the average salary of all workers?
A)It must be $38,000.
B)It must be larger than the median salary.
C)It could be any number between $37,596 and $45,500.
D)None of the above.

Accepted Answer

The average salary of all workers could be any number between $37,596 and $45,500 since we don't have information about the distribution of male and female employees in different industries and job roles. Therefore, we cannot assume that the average salary would be exactly $38,000 or larger than the median salary.

Question 20

The ages (to the nearest year)of the 667 people participating in a large workshop are summarized as shown below.  What is true about the median age?
A)It could be any number between 19 and 20.
B)It must be 20.
C)It must be 21.
D)It must be over 21.

Accepted Answer

The median age is the middle value when the ages are arranged in order from lowest to highest. Since there are 333 people with ages below 20 and 334 people with ages 20 or above, the median age must be the age of the 334th person, which is 20. Therefore, the correct choice is B.

Quiz 1: Looking at Datadistributions

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC. What percentage of women completed at most their junior year?

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC. How many males completed at least some graduate school?

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC. What percentage of men completed at most their freshman year?

On the first day of class,statistics professors ask each student to fill out a demographic questionnaire to learn information about their class.Which of the following variables is/are categorical?

Which of the following variables is quantitative?

The median age of five people in a meeting is 30 years.One of the people,whose age is 50 years,leaves the room.What is the median age of the remaining four people in the room?

On the first day of class,statistics professors ask each student to fill out a demographic questionnaire to learn information about their class.Which of the following variables is/are quantitative?

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC. Approximately how many people are college graduates?

The Environmental Protection Agency records data on the fuel economy of many different makes of cars.Data on the mileage of 20 randomly selected cars are listed below.The values are ordered for convenience. What is the median mileage for these 20 cars?

A researcher reports that,on average,the participants in his study lost 10.4 pounds after 2 months on his new diet.A friend of yours comments that she tried the diet for 2 months and lost no weight,so clearly the report must be a fraud.Which of the following statements is correct?

The bar graph below represents the highest education level achieved for 30 random females and 60 random males questioned on a street in downtown Washington,DC. More men than women are college graduates.

According to the Bureau of Labor and Statistics in 2014,the average salary of all female workers is $37,596.The average salary of all male workers is $45,500.What must be true about the average salary of all workers?

The ages (to the nearest year) of the 667 people participating in a large workshop are summarized as shown below. What is true about the median age?