test

Here are the ages of the male and female employees at First River Bank. Compare the interquartile ranges of the ages of male and female employees.

Male: 7.5 Female: 10

Find the median for the given sample data. The salaries of ten randomly selected doctors are shown below. $142,000 $150,000 $199,000 $229,000 $203,000 $101,000 $111,000 $853,000 $204,000 $152,000

$175,500

Order the following histograms from least to most variability.

(sides the same) (flat chart) (middle low)

31) For twenty days a record store owner counts the number of customers who purchase an album by a 31) certain artist. The data and a dotplot of the data are shown below: Data set: 1, 3, 4, 4, 5, 6, 7, 2, 3, 4, 4, 5, 6, 8, 2, 3, 4, 5, 6, 7, 9 Which of the following statements can be made using the given information?

All of these

In a recent high school poll, the principal asked if students were satisfied with the amount of after-school activities offered. What is the population of interest here?

All students who attend the school.

In a study of 900 adults, 45 out of the 325 men in the study said that they preferred to rent a movie on DVD rather than going out to a movie theater. What is the approximate percentage of men in this study who prefer to rent a movie on DVD?

13.8%

In a study of 1350 elementary school children, 118 out of the 615 girls in the study said they want to be a teacher when they grow up. What percent of girls want to be a teacher when they grow up?

19.2%

Of the adult males surveyed, what percentage had made a clothing purchase in the last thirty days?

50%

What percentage of the participants had a heart rate greater than 130 bpm?

53%

In a study of 1050 adults, 175 out of the 650 women in the study said that they preferred to drive an SUV to driving a compact car. What is the approximate percentage of study participants who are women?

A) 61.9%

The histogram below shows the distribution of pass rates on a swimming test taken by all children who completed a four week summer swim course at the local YMCA. What is the typical pass ratefor the swim test?

About 75%

The following nine values represent race finish times in hours for a randomly selected group of participants in an extreme 10k race (a 10k race with obstacles). Which of the following is closest tothe mean of the following data set? 1.0, 1.2, 1.2, 1.3, 1.4, 1.5, 1.5, 1.7, 2.1

x is about 1.4 hours

A group of junior high athletes was asked what team sport was their favorite. The data are summarized in the table below. On the pie chart, which area would correspond to the category "Volleyball"?

Area B

Marital status of each member of a randomly selected group of adults is an example of what type of variable?

Categorical variable

The ethnicity of the individual respondents in a political poll of a randomly selected group of adults is an example of what type of variable?

Categorical variable

In a survey, married couples were asked, "Do you have children?" The response was electronically recorded as a "1" for yes and a "0" for no. This is an example of

Coded categorical data

A doctor is interested in determining whether a certain medication reduces migraines. She randomly selects 100 people for his study - 50 who will take the medication, and 50 who will take a placebo. The patients are examined once a week for six weeks.

Controlled experiment

A class of 30 introductory statistics students took a quiz worth 100 points. The standard deviation 64) of the scores was 0. What must be true about the students' scores?

Every student received the same score.

According to the following data table, which variable(s) is(are) categorical? Age Gender ShoeSize Ethnicity 18 1 10 1 23 0 7 0

Gender and ethnicity

The fastest 25% of women participants ran the marathon how quickly?

Less than 150 minutes.

What feature of a distribution can NOT be determined from a boxplot?

Number of observations

The average gas mileage of the top selling mini-vans for each U. S. car manufacturer is an example of what type of variable?

Numerical variable

The average number of hours spent completing statistics homework for a randomly selected group of statistics students is an example of what type of variable?

Numerical variable

A doctor is interested in determining whether a certain medication reduces migraines. She reviews her patients' medical records and finds that a higher proportion of people who take the medication have fewer migraines than those who did not take the medication.

Observational study

Indicate whether the study described is an observational study or a controlled experiment. 21) The obesity rates of elementary age children living in urban areas are compared to those living in rural areas to see whether children in urban settings have higher obesity rates.

Observational study

The smoking rates of teens in urban areas are compared to those living in rural areas to see whether teens living in rural settings have higher rates of smoking.

Observational study

When examining distributions of numerical data, what three components should you look for?

Shape, center, and spread

What is the typical value for the histogram shown below?

Since the data are bimodal, there are two typical values - one is about 20 and the other is about 60.

What is the mode response for 2001?

Some College

The U.S. Supreme Court Chief Justice data was used to create the following output in an Excel spreadsheet. Choose the statement that best summarizes the variability of the dataset.

The age of most of the U.S. Supreme Court Chief Justice's since 1900 are within 5.6 years of the mean age.

In the following histogram, what can you conclude about the bin width?

The bin width is too large. We are hiding details of the distribution.

In the following histogram, what can you conclude about the bin width?

The bin width is too small. We are given too much detail.

Pick the statement that best describes the shape of the distribution for the states in the West.

The data appears to be right-skewed with a possible outlier.

Below is the standard deviation for extreme 10k finish times for a randomly selected group of women and men. Chose the statement that best summarizes the meaning of the standarddeviation. Women: s = 0.17 Men: s = 0.21

The distribution of women's finish times is less varied than the distribution of men's finish times.

Suppose we have a data set of the number of car accidents per day in Los Angeles during the year 2013. The data was input into a spreadsheet manually by an assistant at the Department of Transportation. For one day in June 2013, he input that there were 1230 car accidents; but there were actually only 123 that day. How will this error affect the measures of center for this data?

The mean will be higher than it should be, but the median will not be affected.

The distributions of income in the United States is strongly skewed to the right. Which of the following is true?

The median income is smaller than the mean income.

What does it mean to find the mode of a bar chart?

The mode can be found by finding the bar, or category, with the most observations.

Suppose we have a distribution of student exam scores on an easy test. What measure of spread 65) would be best to describe this data?

The spread should be described with the IQR because the distribution will be skewed to the left.

The following histogram represents the movie runtimes (length of a movie in minutes) of 489 movies. What is the typical movie runtime according to this distribution?

The typical value is about 100.

Using the boxplot for the Midwest, determine which of the following statements about the distribution cannot be justified.

There are fewer states with 3887.5 to 6887 prisoners than states with 6887 to 15,706 prisoners.

According to the following two-way table, why are percentages more useful than counts to compare the amount of males and females who take naps?

There are more males than females in the sample.

Based on the histogram below, would it be unusual to be on hold for 5 minutes or more at this call center?

Yes, it would be unusual.

The following data represent the number of cars passing through a toll booth during a certain time period over a number of days. 28 29 27 27 34 28 31 28 29 25 32 29 33 27 31

unknown

Solve the problem. Round monetary amounts to the nearest dollar. Packages of a certain candy vary slightly in weight. Here are the measured weights of nine packages, in ounces: 1.5223 1.5244 1.5251 1.5266 1.4962 1.5248 1.5229 1.5235 1.5258

a. Mean: 1.5213; median: 1.5244 b. 1.4962 is an outlier. c. Mean: 1.5244; median: 1.5246

In what quarter was the revenue the greatest for Year 1?

fourth quarter

400 movie critics rated a movie. The following data give the rating distribution. Rating Frequency Percentage Excellent 80 20% Good 200 50% Fair 120 30%

idk

An international relations professor is supervising four master's students. Information about the students is summarized in the table.

student number: categorical; area of interest: categorical; GPA: numerical

The following data table is organized using which method? Men's Ages. Women's Ages 35. 42 39. 33

this is unstacked data because the ages are separated by groups (in this case, gender).

According to the following two-way table, what percent of people in the sample prefer dogs? Male Female Dog. 40 25 Cat. 25 10

65%

Solve the problem. Two Geometry classes at North Hollywood High School took the same quiz. Mr. Davis had 15 61) students in his class with a mean score of 70. Mrs. Brown's class of 25 students had a mean score of 80. Overall, what was the mean score for all students on the quiz?

74.50

How many people were 23 years old or older?

8 people

What is the difference between a bar chart and a histogram?

A bar chart represents categorical data and a histogram represents numerical data.

How are individual observations recorded in a dotplot, a histogram, and a stemplot?

A dotplot displays a dot for every observation. A histogram uses bars to display intervals of observations. A stemplot displays the actual values of observations.

What is the difference between a histogram and a relative frequency histogram?

A histogram uses counts to record how many observations are in a data set, and a relative histogram uses proportions.

What was the revenue for the second quarter of Year 1?

$25 million

For the pair of histograms below, determine which distribution has the larger standard deviation.

(i) has a larger standard deviation than (ii).

The distribution of the number of times individuals in the 18-24 age group log onto a social networking website during the course of a day tends to be right skewed.

(tail on right side)

Calculate the five-number summary for the following dataset.

19.98, 41.19, 73.295, 83.88, 114.6

Find the standard deviation for the given sample data. Round your answer to one more decimal place than is present in the original data. The top nine scores on the organic chemistry midterm are as follows. 60) 38, 70, 61, 86, 74, 22, 60, 27, 71

22.4

Determine which of the following five variables are numerical and which are categorical. age, gender, height, favorite candy, eye color

Age and height are numerical variables. Gender, favorite candy, and eye color are categorical variables.

A group of cancer patients is divided into two groups. One group is given a new drug to fight the side effects of chemotherapy and the other group is given a placebo. After three months they areasked to respond to a questionnaire about the frequency and severity of their side effects to seewhether the new drug improved the overall negative side effects of chemotherapy.

Controlled experiment

A group of students is divided into two groups. One group listens to classical music while taking a 25) math test and the other group takes the test in silence. The average test scores of the two groups are compared to see whether listening to music during a math test has an effect on scores.

Controlled experiment

The boxplots below represent movie runtimes (length of a movie in minutes) for movies that have 78) been rated by the Motion Picture Association of America as R, PG-13, PG, and G. List ratings according to their median runtimes, from shortest to longest.

G, PG, R, PG-13

A two-way table could be used for which of the following pairs of variables?

Gender and favorite class

Choose the most appropriate measure of center then calculate the typical value rounded to the nearest tenth.

Median; 181.0

Which statement below is NOT supported by the following bar chart?

More males wear sunscreen than females.

The graph below displays the number of applications for a concealed weapons permit in Montcalm County, Michigan, for each of three years. A reporter interprets this graph to mean that applications in 2010 are more than twice the level in 2008. Is the reporter making a correctinterpretation?

No. Although the 2010 bar is more than twice the height of the 2008, the bars do not begin at 0 applications, so the graph does not correctly represent the data. Fifty-five is not equal to two times the number of applications made in 2008.

The bar charts below depict the marital statuses of Americans, separated by gender. Which bar chart shows more variability in marital status? Why?

The female bar chart shows more variability because there are more observations in the different categories than there are for males.

Data was collected on hand grip strength of adults. The histogram below summarizes the data. Which statement is true about the distribution of the data shown in the graph?

The graph shows evidence that two different groups may have been combined into one collection.

A store manager kept track of the number of newspapers sold each week over a seven-week period. The results are shown below. 49, 22, 224, 189, 253, 235, 233

224 newspapers

Based on the boxplot for the West, which of the following is true?

25% of the states sentenced more than 15,706 prisoners.

Determine the interquartile range. The test scores of 19 students are listed below. Find the interquartile range. 91 49 86 70 59 63 97 56 90 78 82 83 54 88 75 41 92 94 66

28

A fitness instructor measured the heart rates of the participants in a yoga class at the conclusion of the class. The data is summarized in the histogram below. There were fifteen people who participated in the class between the ages of 25 and 45. Use the histogram to answer the question. How many participants had a heart rate between 120 and 130 bpm?

3

Ten households were asked how many pets they currently own. The results are shown below. 1 0 2 4 3 2 1 1 6 4

3

What percentage of the sample had texted at least once while driving in the past thirty days?

37.5%

A statistics student collected data from other students in her class who ride a bike to school. The following table shows data about their bikes:

5

Find the mean for the given sample data. Unless otherwise specified, round your answer to one more decimal place than that used for the observations. Last year, nine employees of an electronics company retired. Their ages at retirement are listed 59) below. Find the mean retirement age. 53 61 59 52 67 58 65 50 55

57.8 yr

The histogram below is the distribution of heights for a randomly selected Boy Scout troupe. Choose the statement that is true based on information from the histogram.

All of these are true statements.

Determine if the following scenario is an observational study or a controlled experiment. 26) A doctor is interested in determining whether a certain medication increases the risk of high blood pressure. He randomly selects 100 people for his study - 50 who will take the medication, and 50who will take a placebo. He checks the patients' blood pressures weekly for six months.

Controlled experiment

group of students is divided into two groups. One group is a given a new chewable vitamin and the other group is given a placebo. After six months they are asked to fill out a questionnaire andgiven a health exam to see whether the new vitamin has health benefits that are better than aplacebo.

Controlled experiment