ECO202

The most common type of observational study is a(n) _____.

Survey

Using the above information, what is P(17)?

.06

There is a 60% chance of getting stuck in traffic when leaving the city. On two separate days, what is the probability that you get stuck in traffic both days?

.36

Suppose we flip a fair coin five times and each time it lands heads up. The probability of landing heads up on the next flip is _____.

.5

A professor rolls a fair, six-sided die. Using the classical method of probability, what is the probability that at least three spots will be showing up on the die?

.67

Using the above information, what is the probability that x is greater than or equal to 4 and less than 17?

.73

The probability of at least one head in two flips of a coin is _____.

.75

Using the above information, what is C(17)?

.92

The number of sick days taken (per month) by 200 factory workers is summarized below. The cumulative relative frequency for the class of 11−15 is _____.

.995

Suppose you have a population with N = 3 observations and x 1 = x 2 = x 3 = 5. The population variance is

0

In the data for the cell phone example (see section 3, page 1 of the learning area), the relative frequency of 33 minutes of daily cell phone use is:

0.038

Frequency distributions only apply to populations.

False

In a bar chart the bars are connected from one number to the next.

False

In a bar chart, each bar represents a different observation.

False

In a frequency distribution, the (absolute) frequencies always add up to 100.

False

In a left-skewed distribution, the median is less than the mean.

False

In a uniform distribution, most observations are concentrated near the "middle" of the distribution.

False

In the relative frequency formula for the cell phone example, nis the number of cell phone types.

False

The median is sensitive to outliers.

False

The median tells you something about the amount of variation in your observations, but the mean does not.

False

The sample variance can be negative.

False

When choosing a sample from a population, it is important to avoid doing so randomly.

False

As you collect more data, the range will:

Increase or stay the same

The median of a set of observations is the ____ value.

Middle

Suppose your data contains n = 120 observations. According to the rule-of-thumb for choosing the number of bins, you should use

None of The Above

For the cell phone use data, using the bins [10-19], [20-29],...,[80-89] is

Not Correct

The value of the sum of the squared deviations from the mean, i.e., Σ(x − x̄)2 must always be _____.

at least zero

A probability distribution showing the probability of x successes in n trials, where the probability of success does not change from trial to trial, is termed a _____.

binomial probability distribution

In a questionnaire, respondents are asked to mark their gender as Male, Female, Transgender MtoF, Transgender FtoM, Non-binary, or Intersex. Gender is an example of a(n) _____ variable.

categorical

A researcher is gathering data from four geographical areas designated: South = 1; North = 2; East = 3; West = 4. The designated geographical regions represent _____.

categorical data

Data that provide labels or names for groupings of like items are known as _____.

categorical data

Data collected at the same, or approximately the same, point in time are _____ data.

cross-sectional

All data collected in a study are referred to as the _____.

data set

If several frequency distributions are constructed from the same data set, the distribution with the widest class width will have the _____.

fewest classes

When the data are positively skewed, the mean will usually be _____.

greater than the median

Which of the following is an example of categorical data?

social security number

The variance is equal to the _____.

squared value of the standard deviation

A statistics professor asked students in a class their ages. Based on this information, the professor states that the average age of students in the university is 21 years. This is an example of _____.

statistical inference

The process of analyzing sample data to draw conclusions about the characteristics of a population is called _____.

statistical inference

Which of the following is NOT a measure of location?

variance

The symbol σ 2 is used to represent the _____.

variance of a population

The _____ denotes the number of standard deviations xi is from the mean x̄.

z-score

The Department of Transportation of a city has noted that on the average there are 14 accidents per day. The average number of accidents is an example of _____.

descriptive statistics

The summaries of data, which may be tabular, graphical, or numerical, are referred to as _____.

descriptive statistics

A nice visualization tool for histograms can be found at https://istats.shinyapps.io/EDA_quantitative/. You can enter data in a box on the left side of the page, and explore what the histogram would look like if you changed the bin width (using the bin width slide below the data box) and the number of bins. Type the following data values into the data box (separated by a space instead of a comma): 5, 2, 3, 11, 12, 6, 7, 6, 9, 3, 3, 4, 7, 6, 10, 6, 4, 6. How many bins do you get when you select a bin width of 1.01?

10

Of five letters (A, B, C, D, and E), two letters are to be selected at random. How many possible selections are there?

10

What is the expected value of the sum of three dice?

10.5

How many possible values can the random variable x take on?

16

In a sample of 50 people, the proportion of those with blue eyes is 32%. How many people in the sample have blue eyes?

16

What is P(16)?

2.78%

An experiment has three steps with three outcomes possible for the first step, two outcomes possible for the second step, and four outcomes possible for the third step. How many experimental outcomes exist for the entire experiment?

24

How many ways can the sum of three dice add up to a 10?

27

Suppose that x1 = 5, x2 = 3, x3 = 1, x4 = -2 and x5 = 4. Then ∑ i = 3 5 x i is equal to

3

What is the expected value of a single die roll?

3.5

What is the standard deviation of a single die roll?

3.50

Suppose that the population had a 5th observation, x 5 = 12, in addition to the observations in the table above. The variance is then ____.

4.8

Suppose the population variance is σ 2 = 25. Then σ = ___

5

College students were surveyed to determine how much they planned to spend in various categories during the upcoming academic year. One category is the amount spent on school supplies. The graphs below show the amount of money spent on school supplies by women and men. Approximately what percent of women spend more than $105 on school supplies?

5%

How many bins do you get when you select a bin width of 2?

6

The sample mean is based on fewer observations than the population mean.

60%

The Tennessean, an online newspaper located in Nashville, Tennessee, conducts a daily poll to obtain reader opinions on a variety of current issues. In a recent poll, readers responded to the following question: "If a constitutional amendment to ban a state income tax is placed on the ballot in Tennessee, would you want it to pass?" Possible responses were Yes, No, or Not Sure (The Tennessean website). What was the sample size for this poll? Round your answer to the nearest whole number. Are the data categorical or quantitative? Would it make more sense to use averages or percentages as a summary of the data for this question?

762 Categorical Percentages

The mean of 6, 13, and 5 is:

8

The variance of a sample of 81 observations is 64. The standard deviation of the sample is which of the following?

8

Twenty percent of people at a company picnic got food poisoning. What percent of the people at the picnic did NOT get food poisoning?

80%

Assume your favorite football team has two games left to finish the season. The outcome of each game can be win, lose, or tie. The number of possible outcomes is _____.

9

Suppose you have 4 observations: 9, 6, 15 and 10. The median is ___.

9.5

What is C(16)?

98.15%

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

A histogram displays quantitative data, while a bar graph displays categorical data.

What organization developed the report, "Ethical Guidelines for Statistical Practice"?

American Statistical Association

What sort of model is NOTused in the video to illustrate levels of development?

Boat

J.D. Power and Associates surveys new automobile owners to learn about the quality of recently purchased vehicles. The following questions were asked in the J.D. Power Initial Quality Survey. Comment on whether each question provides categorical or quantitative data. Did you purchase or lease the vehicle? What price did you pay? What is the overall attractiveness of your vehicle's exterior? (Unacceptable, Average, Outstanding, or Truly Exceptional) What is your average number of miles per gallon? What is your overall rating of your new vehicle? (1- to 10-point scale with 1 Unacceptable and 10 Truly Exceptional)

Categorical Quantitative Categorical Quantitative Quantitative

The Microsoft Office package used to perform statistical analysis is _____.

Excel

A frequency distribution is a count of the total number of observations in your data.

False

A population is a subset of a sample.

False

A random variable always takes on the same number.

False

A set of observations either has no mode, or multiple modes.

False

Pelican Stores You are a marketing manager for Pelican Stores, a division of National Clothing that sells women's apparel throughout the country. Over the past few months, you initiated and executed a promotion whereby discount coupons were sent to customers of other National Clothing stores. Now, after the promotion ended, data has been collected resulting in a sample of 100 in-store credit card transactions at Pelican during one day when the promotion was running. In the dataset, the Proprietary Card method of payment refers to charges made using a National Clothing charge card (store- issued card). Customers who made a purchase using a discount coupon are referred to as Promotional Customers and customers who made a purchase but did not use a discount coupon are referred to as Regular Customers. Because you did not send promotional coupons to regular Pelican Store customers, you consider sales made to people presenting the promotional coupon as sales the store would not had made otherwise; they usually shop elsewhere. Of course, the goal of your marketing strategy is to turn these new customers who used the coupon into regular customers at Pelican Stores. You are tasked with learning more about your customer base and evaluating the effectiveness of the promotion by presenting the sample data in a manner that effectively communicates your findings. This will require using the appropriate tabular or graphical display for the data type you wish to present. You determine that another interesting metric to analyze would be the relationship between the "Type of Customer" variable and the "Method of Payment" variable. To examine this relationship you develop the crosstabulation below:

Promotional Customers using a Proprietary Card accounted for greater than 80% of all Promotional Sales dollars and nearly 61% of total sales dollars. Since so many new customers made purchases on their Proprietary Cards, the marketing effort appears to be a success.

A portion of the population selected to represent the population is called _____.

Sample

What topic is used when discussing the need for relative figures as opposed to absolute figures?

Soldiers

What event does Hans Rosling mention when there is a big "drop" in life expectancy?

Spanish flu

The symbol k is

The number of bins

Which of the following is NOT a property of a binomial experiment?

The probabilities of the two outcomes can change from one trial to the next.

A bar chart can represent either an absolute or a relative frequency distribution, whereas a pie chart represents a relative frequency distribution.

True

A random variable can take on a number of different possible values.

True

In a left-skewed distribution, there are some extremely small/low observations.

True

In a symmetric frequency distribution, the mean and median are equal.

True

The range is based on 2 observations in your data.

True

The sample standard deviation is s = 1.5. This implies that σ 2 is equal to

Unknown

In order to prevent missing an observation we should always round bins:

Up

Which of the following is NOT an example of descriptive statistics?

an estimate of the number of Alaska residents who have visited Canada

The mean of the sample _____.

is affected by outliers

Statistical inference _____.

is the process of drawing inferences about the population based on the information taken from the sample

Generally, which of the following is the least appropriate measure of central tendency for a data set that contains outliers?

mean

After the data have been arranged from smallest value to largest value, the value in the middle is called the _____.

median

Which of the following symbols represents the size of a sample?

n

Which of the following graphical methods is most appropriate for categorical data?

pie chart

The standard deviation is the _____.

positive square root of the variance

The birth weight of newborns, measured in grams, is an example of _____.

quantitative data

Suppose you have a sample of 11 observations. The median is ______ in the ordered list.

the 6th observation

In a cumulative frequency distribution, the last class will always have a cumulative frequency equal to _____.

the total number of elements in the data set