BUS 220 (Test 1, chapters 1-5)

Each salesperson in a large department store chain is rated on their sales ability and their potential for advancement. The data for the 500 sampled salespeople are summarized in the following table. 0.27 0.30 0.404 0.45

0.30

A survey of top executives revealed that 35% of them regularly read Time magazine, 20% read Newsweek and 40% read U.S. News & World Report. Ten percent read both Time and U.S. News & World Report. What is the probability that a particular top executive reads either Time or U.S. News & World Report regularly? 0.85 0.06 1.00 Correct 0.65

0.65

A sample of single persons receiving social security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839 and $965. How many observations are below the median? 0 1 2 3 3.5

3 6 (total observations)/ 2=3

A box plot graphically shows the 10th and 90th percentiles. True False

False

A combination of a set of objects is defined by the order of the objects. True False

False

In a distribution, the second quartile corresponds with the Mean. Median. Mode. Variance.

Median

A question in a market survey asks for a respondent's favorite car color. Which measure of central location should be used to summarize this question? Mode Median Mean Standard deviation

Mode

Refer to the following breakdown of responses to a survey of "Are you concerned about being tracked while connected to the Internet"? Response Frequency Very concerned 140 Somewhat Concerned 40 No concern 20 What is the class interval for the frequency table above? 10 20 40 None of the above

None of the above

What are the major characteristics of Range?

Range is the simplest measure of dispersion. It is limited though because it only uses two values: the maximum and minimum value. To find the range of a set of values, you simply subtract the minimum value from the maximum value. Since it is so easy to calculate its value, range is widely used in production management and control applications.

A dot plot shows the The general shape of a distribution. The mean, median, and mode. The relationship between two variables. The interquartile range.

The general shape of a distribution.

To apply the special rule of addition, the events must be mutually exclusive True False

True

A box plot shows the relative symmetry of a distribution. True False

True

In a stem-and-leaf display, the leaf represents the members of a class in a frequency distribution. True False

True

Percentiles divide a distribution into one hundred equal parts. True False

True

Quartiles divide a distribution into four equal parts. True False

True

To construct a pie chart, relative class frequencies are used to graph the "slices" of the pie. True False

True

To infer something about a population, we usually take a sample from the population False True

True

A bottling company offers three kinds of delivery service - instant, same day and within five days. The profit per delivery varies according to the kind of delivery. The profit for an instant delivery is less than the other kinds because the driver has to go directly to a grocery store with a small load and return to the bottling plant. To find out what effect each type of delivery has on the profit picture, the company summarized the data in the following table based on deliveries for the previous quarter. What is the weighted mean profit per delivery? $72 $110 $142 $97 $66.67

$97 Sum number of deliveries (200), times profit delivery gives sum of total weight, so divided total weight (19400/200=97)

A pie chart is similar to a relative frequency distribution. True False

True

Each salesperson in a large department store chain is rated on their sales ability and their potential for advancement. The data for the 500 sampled salespeople are summarized in the following table. (Picture) What is the probability that a salesperson selected at random will have below average sales ability and fair potential for advancement? 0.032 0.10 0.16 0.32

0.032 Total number of people surveyed = 500 number of people who have below average sales ability and fair potential for advancement = 16 The probability that a salesperson selected at random will who have below average sales ability and fair potential for advancement is

A gumball machine has just been filled with 50 black, 150 white, 100 RED and 100 yellow gum balls that have been thoroughly mixed. Sue and Jim, each, purchased one gumball. What is the likelihood both Sue and Jim get RED gumballs? 0.50 0.062 0.33 0.75

0.062 total balls = 50+150+100+100 = 400 required probability = (100red/400total) * (99/399) = 0.062

In a finance class, the final grade is based on three tests. Historically, the instructor tells the class that the joint probability of scoring "A"'s on the first two tests is 0.5. A student assigns a probability of 0.9 that she will get an "A" on the first test. What is the probability that the student will score an "A" on the second test given that she scored an "A" on the first test? 0.50 0.95 0.55 0.90

0.55 0.5/0.9=0.55

Six basic colors are used in decorating a new condominium. They are applied to a unit in groups of four colors. One unit might have gold as the principal color, blue as a complementary color, red as the accent color and touches of white. Another unit might have blue as the principal color, white as the complementary color, gold as the accent color and touches of red. If repetitions are permitted, how many different units can be decorated? 7,825 25 125 1,296

1,296 6^4 (six base colors to the power of the four grouped colors)

Chebyshev's Theorem

1- (1/k^2) 75% 2 SD 89% 3 SD 96% 5 SD

What level of measurement is a person's "favorite sport"? Ratio Ordinal Interval Nominal

Nominal

A tire manufacturer advertises, "the median life of our new all-season radial tire is 50,000 miles. An immediate adjustment will be made on any tire that does not last 50,000 miles." You purchased four of these tires. What is the probability that all four tires will wear out before traveling 50,000 miles? 1/10 or 0.10 ¼ or 0.25 1/64 or 0.0156 1/16 or 0.0625

1/16 or 0.0625 1/2x1/2x1/2x1/2=1/16=0.0625

A board of directors consists of eight men and four women. A four-member search committee is randomly chosen to recommend a new company president. What is the probability that all four members of the search committee will be women? 1/120 or 0.00083 1/16 or 0.0625 ⅛ or 0.125 1/495 or 0.002

1/495 or 0.002 We have chosen all four members of the search committee will be women = 4 C 4 / 12 C 4 = nCr(4,4)/nCr(12,4) 1/495 = 0.00202

How many permutations of the two letters C and D are possible? 1 0 2 8

2

A lamp manufacturer has developed five lamp bases and four lampshades that could be used together. How many different arrangements of base and shade can be offered? 5 10 15 20

20 (4x5)

The ABCD football association is considering a Super Ten Football Conference. The top 10 football teams in the country, based on past records, would be members of the Super Ten Conference. Each team would play every other team in the conference during the season and the team winning the most games would be declared the national champion. How many games would the conference commissioner have to schedule each year? (Remember, Oklahoma versus Michigan is the same as Michigan versus Oklahoma.) 45 50 125 14

45 The first team would play nine games with rest nine teams, the second would play eight and so on. And the tenth team would not play any more game because it is already counted. So the total games would be 9+8+7+6+5+4+3+2+1=45

The numbers 0 through 9 are used in code groups of four to identify an item of clothing. Code 1083 might identify a blue blouse, size medium. The code group 2031 might identify a pair of pants, size 18, and so on. Repetitions of numbers are not permitted, i.e., the same number cannot be used more than once in a total sequence. As examples, 2256, 2562 or 5559 would not be permitted. How many different code groups can be designed? 5,040 620 10,200 120

5040 = 10x9x8x7 = 5040

You have the assignment of designing color codes for different parts. Three colors are used on each part, but a combination of three colors used for one part cannot be rearranged and used to identify a different part. This means that if green, yellow and violet were used to identify a camshaft, yellow, violet and green (or any other combination of these three colors) could not be used to identify a pinion gear. If there are 35 combinations, how many colors were available? 5 7 9 11

7 nC3 =35 n(n-1)(n-2)=35*6 =210 n^3-3n^2+2n-210=0 n=7

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

A bar chart shows the frequency for the distribution of a qualitative variable. A pie chart shows the relative frequency for the distribution of a qualitative variable. The pie chart is also a great way to make a visual message of the proportions that each variable contributes to the total observations

What is the difference between a frequency distribution and a cumulative frequency distribution?

A frequency distribution shows the number of observations in each class. A cumulative frequency distribution shows the sum of the number of observations in a class plus all lower-ranked or -valued classes.

When data is collected using a qualitative, nominal variable, what is true about a frequency distribution that summarizes the data? -Upper and lower class limits must be calculated. -A pie chart can be used to summarize the data. -Number of classes is equal to the number of variable's values plus 2. -The "5 to the k rule" can be applied.

A pie chart can be used to summarize the data. A pie chart is used to show the relative frequency for a qualitative, nominal variable. The statements "the upper and lower class limits must be calculated" and "the "5 to the k rule" can be applied" apply to quantitative variables.

A dot plot is best applied when The mean, median and mode are equal. The general shape of a distribution is symmetric. The relationship between two variables is summarized. A single variable is summarized.

A single variable is summarized.

Which of the following measures of dispersion are based on deviations from the mean? Variance Standard deviation Mean deviation All of the above

All of the above

Sometimes, data has two values that have the highest and equal frequencies. In this case, the distribution of the data can best be summarized as symmetric bimodal (having two modes) positively skewed negatively skewed

Bimodal (having two modes)

The process used to calculate the probability of an event given additional information has been obtained through Bayes' theorem. classical probability. permutation. subjective probability

Bayes' theorem.

The interquartile range is graphically presented in a Dot plot. Stem-and-leaf display. Box plot. Contingency table

Box plot.

Which approach to probability assumes that the events are equally likely? Classical Empirical Subjective Mutually exclusive

Classical

A contingency table would be used to summarize data such as Company employees by gender and organizational title. Company employees by gender and age. Company employees by compensation and age. Company employees by compensation and years with the company

Company employees by gender and organizational title.

When an event's probability depends on the likelihood of another event, the probability is a(n) conditional probability. empirical probability. joint probability. mutually exclusive probability.

Conditional probability.

Refer to the following breakdown of responses to a survey of "How confident are you that you saved enough to retire"? Response Frequency Very confident 63 Somewhat confident 135 Not very confident 99 Don't know 3 What is the class interval for the frequency table above? A. 10 B. 20 C. 40 D. None Apply

D. None Apply There is no class interval for data measured on an ordinal scale

What is the difference between discrete and continuous data?

Discrete data is counted, can only take certain values, like the number of students in a class, rolling a dice (it only has certain values in it). Continuous data is measured--can take any value within a specific range (minutes, fractions, heights, etc).

A relationship between gender and preference for Coke or Pepsi can be best represented by a scatter diagram True False

False

A scatter diagram of sales versus production may be constructed by plotting the minimum, first quartile, median, third quartile, and the maximum values of each variable True False

False

Quartiles divide a distribution into ten equal parts. True False

False (four parts)

A dot plot is an easy way to represent the relationship between two variables. True False

False Dot Plot is a graph for displaying the distribution of numerical variables where each dot represents a value. For whole numbers, if a value occurs more than once, the dots are placed one above the other so that the height of the column of dots represents the frequency for that value.

The coefficient of skewness is the standard deviation divided by the mean True False

False Pearsons formula= 3(mean-median)/S.D.

A frequency distribution for qualitative data has class limits. True False

False Quantitative has limits, qualitative does not.

In a frequency distribution, the number of observations in a class is called class midpoint interval array frequency

Frequency

What is the difference between a nominal and ordinal scale?

Nominal scale is where data is classified into categories and has no particular order (eye color, gender, religion), observations of qualitative variable can only be classified and counted--categorical without implying order. Ordinal scale is also categorical but there is some order rank to it. Data values are not determined but are represented by sets of labels or names (high, medium, low, i.e.).

Which one of the following is NOT an example of discrete data? Number of households watching the Home Shopping Network. Number of employees reporting in sick. Number of miles between New York City and Chicago. Number of members of the Denver Lions Club

Number of miles between New York City and Chicago.

A bank asks customers to evaluate the drive-thru service as good, average, or poor. Which level of measurement is this classification? Nominal Ordinal Interval Ratio

Ordinal

In a management trainee program, 80 percent of the trainees are female, 20 percent male. Ninety percent of the females attended college, 78 percent of the males attended college. A management trainee is selected at random. What is the probability that the person selected is a male who did NOT attend college? P (male) P (did not attend college | male) P (did not attend college) P (male | did not attend college) P (male) P (did not attend college) P (did not attend college)

P (male) P (did not attend college | male)

An individual can assign a subjective probability to an event based on the individual's knowledge about the event. True False

True

A small sample of computer operators shows monthly incomes of $1,950, $1,775, $2,060, $1,840, $1,795, $1,890, $1,925 and $1,810. What are these ungrouped numbers called? Histogram Class limits Class frequencies Raw data

Raw data Histograms and frequency distributions summarize data. The data in the question are the individual observations that are not summarized.

How to read and answer questions from ogive

Sometimes called a cumulative frequency polygon, is a type of frequency polygon that shows cumulative frequencies. In other words, the cumulative percents are added on the graph from left to right.

To locate the percentile for a given observation in a data set, the data must be Sorted and listed from the minimum to the maximum values. Displayed in a histogram. Summarized in a cumulative frequency distribution. Distributed symmetrically around the mean.

Sorted and listed from the minimum to the maximum values.

What are the major characteristics of Standard Deviation?

Standard deviation is the square root of the variance. Both variance and standard deviation are nonnegative and are zero only if all observations are the same. Both are also a measure of deviation, versus range which is a measure of dispersion

The general process of gathering, organizing, summarizing, analyzing, and interpreting data is called Statistics. Descriptive statistics. Inferential statistics. Levels of measurement.

Statistics

The main purpose of descriptive statistics is to: Summarize data in a useful and informative manner. Make inferences about a population. Determine if the data adequately represents the population. Gather or collect data.

Summarize data in a useful and informative manner.

How to read the-stem-and-leaf display

The "stem" values are listed down, and the "leaf" values go right (or left) from the stem values. The "stem" is used to group the scores and each "leaf" shows the individual scores within each group.

What statistics are needed to draw a box plot? The minimum, maximum, median, first and third quartiles. The median, mean and standard deviation. The median and interquartile range. The mean and standard deviation.

The minimum, maximum, median, first and third quartiles.

A purchasing agent for a trucking company is shopping for replacement tires for their trucks from two suppliers. The suppliers' prices are the same. However, Supplier A's tires have an average life of 60,000 miles with a standard deviation of 10,000 miles. Supplier B's tires have an average life of 60,000 miles with a standard deviation of 2,000 miles. Which of the following statements is true? The two distributions of tire life are the same On average, Supplier A's tires have a longer life then Supplier B's tires The life of Supplier B's tire is more predictable than the life of Supplier A's tires The dispersion of Supplier A's tire life is less than the dispersion of Supplier B's tire life

The life of Supplier B's tire is more predictable than the life of Supplier A's tires The smaller the standard deviation, the more accurate it is.

A stem-and-leaf display includes the following row: 3 | 0 1 3 5 7 9. Assume that the data is rounded to the nearest whole number. The frequency of the class is seven. The minimum value in the class is 0. The maximum value in the class is 39. The class interval is 5.

The maximum value in the class is 39.

An experiment may have: Only one outcome Only two outcomes Two or more outcomes Several events

Two or more outcomes

In a scatter diagram, we describe the relationship between Two variables measured at the ordinal level. Two variables, one measured as an ordinal variable and the other as a ratio variable. Two variables measured at the interval or ratio level. A variable measure on the interval or ratio level and time.

Two variables measured at the interval or ratio level.

The sum of the differences between sample observations and the sample mean is Zero The mean deviation The range The standard deviation

Zero (Because all deviations from sample mean = 0)

Using the terminology of Bayes' Theorem, a posterior probability can also be defined as a conditional probability a joint probability 1 0

a conditional probability (mathematical formula for determining conditional probability. The theorem provides a way to revise existing predictions or theories given new or additional evidence)

When an experiment is conducted "without replacement," events are dependent events are equally likely the experiment can be illustrated with a Venn Diagram the probability of two or more events is computed as a joint probability

events are dependent

The probability of two or more events occurring concurrently is called a(n) conditional probability. empirical probability. joint probability. tree diagram.

joint probability.

Monthly commissions of first-year insurance brokers are $1,270, $1,310, $1,680, $1,380, $1,410, $1,570, $1,180 and $1,420. These figures are referred to as: histogram. raw data. frequency distribution. frequency polygon.

raw data.

A pie chart shows the -relative frequencies of a qualitative variable. -relative frequencies of a quantitative variable. -frequencies of a nominal variable. -frequencies of a ratio variable.

relative frequencies of a qualitative variable.

Refer to the following wage breakdown for a garment factory. Hourly wages Number of Wage Earners $4 up to $7 18 7 up to 10 36 10 up to 13 20 13 up to 16 6 What is the class midpoint for the class with the greatest frequency? $5.50 $8.50 $11.50 $14.50

$8.50 The class with the greatest frequency is "7 up to 10." The class midpoint is the lower limit (7) plus half of the class interval (1/2 × 3 = 1.5) or $7 + 1.5 = $8.50.

A sample of experienced typists revealed that their mean typing speed is 87 words per minute and the median is 73. The standard deviation is 16.9 words per minute. What is the Pearson's coefficient of skewness? -2.5 -4.2 +4.2 +2.5

+2.5 3(mean-median)/S.D. 3(88-74)/16.9=+2.5

Ages (rounded to the nearest whole year) of employees at a large company were grouped into a distribution with the following class limits: 40 up to 50 50 up to 60 60 up to 70 What is the class interval? 9 10 10.5 11

10 The class interval is the difference between the lower or upper class limits of adjacent classes

The weights (in grams) of the contents of several small bottles are 4, 2, 5, 4, 5, 2 and 6. What is the sample variance? 6.92 4.80 1.96 2.33

2.33 SAMPLE VARIANCE=(4^2+2^2+5^2+4^2+5^2+2^2+6^2= 126 126-(28)^2/7)=14 14/(7-1)=2.33

Refer to the following frequency distribution on days absent during a calendar year by employees of a manufacturing company: Days absent Number of Employees 0 up to 3 60 3 up to 6 31 6 up to 9 14 9 up to 12 6 12 up to 15 2 How many employees were absent from 6 up to 12 days? 20 8 12 17

20

Refer to the following breakdown of responses to a survey of "How confident are you that you saved enough to retire"? Response Frequency Very confident 63 Somewhat confident 135 Not very confident 99 Don't know 3 What percent of the responses indicated that users were very confident? 63% 21% 45% 33%

21% Total frequency (300) divided by the very confident amount (63) = .21

The Investment Research Institute reported in its Mutual Fund Fact Book that the number of mutual funds increased from 5725 in 1999 to 7977 in 2009. What is the geometric mean annual percent increase in the number of funds? 1.034 3.37 39.34 71.77 633.5

3.37 (7977/5725)^(1/10years)-1=3.37%

Refer to the following breakdown of responses to a survey of room service in a hotel. Response Frequency Not satisfied 20 Satisfied 40 Highly satisfied 60 What percent of the responses indicated that customers were satisfied? 40% 33% 50% 100%

33% 40/120=0.33

Ten experts rated a newly developed chocolate chip cookie on a scale of 1 to 50. Their ratings were: 34, 35, 41, 28, 26, 29, 32, 36, 38 and 40. What is the mean deviation? 8.00 4.12 12.67 0.75

4.12

Empirical Rule

68% +/- 1 Standard Deviation, 95% +/- 2 Standard Deviation, 99.7% +/- 3 Standard Deviation

How to read and answer questions from histogram

A histogram is a plot that shows the underlying frequency distribution (shape) of a set of continuous data--there are no gaps in the data. This allows the inspection of the data for its underlying distribution (e.g., normal distribution), outliers, skewness, etc. Histogram presents numerical data whereas bar graph shows categorical data

What is the difference between a sample and population?

A population is the set of all measurements of interest to the investigator. A sample is any subset of measurements selected from the population.

A student was interested in the cigarette smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table: Males who smoke 20 Males who don't smoke 30 Females who smoke 25 Females who don't smoke 50 What type of chart best represents the frequency table? Bar Chart Pie Chart Scatter plot Frequency Polygon

Bar Chart

A disadvantage of using an arithmetic mean to summarize a set of data is that the arithmetic mean Sometimes has two values. Can be used for interval and ratio data. Is always different from the median. Can be biased by one or two extremely small or large values.

Can be biased by one or two extremely small or large values.

What type of variable is "pounds of popcorn" served at a movie theater? Interval Ratio Discrete Continuous

Continuous

The reported unemployment is 5.5% of the population. What measurement scale is used to measure unemployment? Nominal Ordinal Interval or ratio Descriptive

Interval or ratio

The sum of the deviations of each data value from this measure of central location will always be zero. Mode Mean Median Standard deviation

Mean

On a survey questionnaire, students were asked to indicate their class in college. If there were only four choices from which to choose, which measure(s) of central location would be appropriate to use for the data generated by that questionnaire item? Mean and median Mean and mode Mode and median Mode only

Mode and median

Which measures of central location are not affected by extremely small or extremely large values? Mean and median Mean and mode Mode and median Standard deviation and mean

Mode and median

A marketing class of 50 students evaluated the instructor using the following scale: superior, good, average, poor, and inferior. The descriptive summary showed the following survey results: 2% superior, 8% good, 45% average, 45% poor, and 0% inferior. The instructor's performance was great! The instructor's performance was inferior. Most students rated the instructor as poor or average. No conclusions can be made.

Most students rated the instructor as poor or average.

Shoe style is an example of what level of measurement? Nominal Ordinal Interval Ratio

Nominal

What are the major advantages of a stem-and-leaf display over a histogram? (Remember that both graphs display quantitative values)

The main advantage of a stem and leaf plot is that the data are grouped and all the original data are shown, too-- 'we don't lose the identity of each observation'. The data is also usually ordered from smallest to largest and specific values can be retrieve from it. In simple words, a histogram shows the frequencies of the class interval and a steam-and-leaf shows that plus the data values. One more advantage of a steam-and-leaf is that it is easier to construct handy tallies and display by hand small sets of values.

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

The major difference is that a histogram is only used to plot the frequency of score occurrences in a continuous data set that has been divided into classes, called bins. Bar charts, on the other hand, can be used for a great deal of other types of variables including ordinal and nominal data sets.

Dispersion describes the degree of variation in the data True False

True

Pearson's coefficient of skewness is a measure of a distribution's symmetry. True False

True

Statistics are used as a basis for making decisions. True False

True

The average number of passengers on commercial flights between Chicago and New York City is an example of a statistic True False

True

The branch of mathematics used to facilitate the collection, organization, presentation, analysis and interpretation of numerical information is referred to as statistics True False

True

When data is collected using a quantitative, ratio variable, what is true about a frequency distribution that summarizes the data? -Upper and lower class limits must be calculated. -A pie chart can be used to summarize the data. -Number of classes is equal to the number of variable's values plus 2. -The "5 to the k rule" can be applied.

Upper and lower class limits must be calculated. The statements "a pie chart can be used to summarize the data" and "the number of classes is equal to the number of variable's values" refer to frequency distributions for qualitative variables. For quantitative, ratio variables, the number of classes, the class interval, and class limits must be computed.

Refer to the following breakdown of responses to a survey of "Are you concerned about being tracked while connected to the Internet"? Response Frequency Very concerned 140 Somewhat Concerned 40 No concern 20 What is the class with the greatest frequency? Very concerned Somewhat concerned No concern None of the above

Very concerned

Production of passenger cars in Japan increased from 3.94 million in 1999 to 6.74 million in 2009. What is the geometric mean annual percent increase? 4.0 1.9 5.5 16.6 47.3

5.5

The lengths of time (in minutes) several underwriters took to review applications for similar insurance coverage are: 50, 230, 52 and 57. What is the median length of time required to review an application? 54.5 141.0 97.25 109.0

54.5 (52+57/2=54.5)

Why use a sample instead of using the population data?

A sample is easier to collect that trying to collect the whole data of a population, it is cheaper to do and take less time. (due to economic (costs) and practical constraints we usually cannot make measurements on every single member of the population in which we are interested. Consequently, we make observations on a sample from the population and then make inference about the population as a whole.)

The number of employees less than the upper limit of each class at Lloyd's Fast Food Emporium is shown in the following table: Ages Cummulative Number 18 up to 23 6 23 up to 28 19 28 up to 33 52 33 up to 38 61 38 up to 43 65 What is it called? A. A histogram B. A cumulative frequency table C. A pie chart D. A frequency polygon

B. A cumulative frequency table The table shows the number of employees in each class or less. So each class frequency is a cumulative total and the table is a cumulative frequency table.

Refer to the following breakdown of responses to a survey of room service in a hotel. Response Frequency Not satisfied 20 Satisfied 40 Highly satisfied 60 What type of chart should be used to describe the frequency table? Pie chart Bar chart Histogram Frequency Polygon

Bar chart

How to read and answer questions from bar chart

Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger.

What is a disadvantage of the range as a measure of dispersion? Based on only two observations Can be distorted by a large mean Not in the same units as the original data Has no disadvantage

Based on only two observations

What is the difference between an interval and a ratio scale?

Both are numerical, but interval is ordered according to the amount of characteristics it posses and the variables can be added and subtracted, there is no zero point (women's dresses, body's temperatures), ratio scale has a natural zero, differences and ratios are meaningful, the highest level of measurement, and ratio variables can be multiply or divided (heights, weight, age, income statements, etc.)

When are events mutually exclusive or Independent?

Events are mutually exclusive when the occurrence of one event means that none of the other events can occur at the same time. For example, when rolling a dice it will result in a number being odd or even but not both on the same roll. Independent events are the occurrence of one event that has no effect on the probability of occurrence of another event. For example, flipping a coin and getting heads, then flipping it again and getting heads again, has nothing to do with the first time the coin was flipped. Both events happened individually of each other.

Descriptive statistics are used to find out something about a population based on a sample False True

False

Extremely high or low scores affect the value of the median. True False

False

For any distribution, there are an equal number of values above and below the mean. True False

False

The order that runners finish in a race would be an example of continuous data. False True

False

The ordinal level of measurement is considered the "lowest" level of measurement. True False

False

The terms descriptive statistics and inferential statistics can be used interchangeably False True

False

What is the following table called? Ages Numbers of ages 20 up to 30 16 30 up to 40 25 40 up to 50 51 50 up to 60 80 Histogram Frequency polygon Cumulative frequency distribution Correct Frequency distribution

Frequency distribution

How are statistical questions investigated?

In four stages: 1. Pose a question 2. Collect relevant data (chose a sample, design a question, conduct an experiment) 3. Analyze the data (calculate, descriptive statistics, draw a graph, calculate averages, variance, etc.) 4. Interpret the result (test for cause-and-effect, make a prediction, make a decision--accept or reject?)

The Equal Employment Opportunity Act requires employers to classify their employees by gender and national origin. Which level of measurement is this? Nominal Ordinal Interval Ratio

Nominal

The members of each basketball team wear numbers on their jerseys. What scale of measurement are these numbers considered? Nominal Ordinal Interval Ratio

Nominal

When a class interval is expressed as: 100 up to 200, -Observations with values of 100 are excluded from the class. -Observations with values of 200 are included in the class. -Observations with values of 200 are excluded from the class. -The class interval is 99.

Observations with values of 200 are excluded from the class.

A group of women tried five brands of finger nail polish and ranked them according to preference. What level of measurement is this? Ordinal Interval Ratio Nominal

Ordinal

Respondents were asked, "Do you now earn more than or less than you did five years ago?" What is this level of measurement? Ordinal Interval Ratio Nominal

Ordinal

What type of chart should be used to show relative class frequencies? Pie chart Bar chart Histogram Frequency Polygon

Pie chart

A student was studying the political party preferences of a university's student population. The survey instrument asked students to identify their political preference, for example, democrat, republican, libertarian, or other party. The best way to illustrate the relative frequency distribution is a Bar chart. Pie chart. Histogram. Frequency polygon

Pie chart. Political preference is a qualitative, nominal variable. Frequencies for a qualitative, nominal variable are best presented with a bar chart.

How to read and answer questions from pie chart.

Pie charts are best to use when you are trying to compare parts of a whole. They do not show changes over time

What type of variable is the number of robberies reported in your city? Attribute Continuous Quantitative Qualitative

Quantitative

The incomes of a group of 50 loan applicants are obtained. Which level of measurement is income? Nominal Ordinal Interval Ratio

Ratio

How to read and answer questions from frequency polygon.

Similar to a histogram, constructed using the midpoints from the information given, and unlike a histogram, you can compare multiple frequency polygons in the same graph (allows you to compare different sets of data)

In the calculation of the arithmetic mean for grouped data, which value is used to represent all the values in a particular class? The upper limit of the class. The lower limit of the class. The frequency of the class. The cumulative frequency preceding the class. The class midpoint.

The class midpoint

What is the relationship among the mean, median and mode in a symmetric distribution? They are all equal The mean is always the smallest value The mean is always the largest value The mode is the largest value

They are all equal

Why are unequal class intervals sometimes used in a frequency distribution? -To avoid a large number of empty classes -For the sake of variety in presenting the data -To make the class frequencies smaller -To avoid the need for midpoints

To avoid a large number of empty classes

A dot plot is useful for showing possible outliers. True False

True

A frequency distribution groups data into classes showing the number of observations in each class. True False

True

A population is a collection of all individuals, objects, or measurements of interest. False True

True

A sample is a portion or part of the population of interest. True False

True

Three persons earn $8 an hour, six earn $9 an hour, and one earns $12 an hour. The weighted mean hourly wage is $9. True False

True

What are the major characteristics of Variance?

Variance, unlike range, uses all the data points to measure dispersion. It is defined as the arithmetic mean of the squared deviations from the mean. It is calculated by taking the arithmetic mean of the squared differences between each value and the mean value