STATS
A city in California spent $6 million repairing damage to its public buildings in Year 1. The following table shows the categories where the money was directed. How much more did the city spend to fix damage caused by termites compared to the damage caused by water? (HW2 Q 17)
$960,000
Consider the following frequency distribution. What proportion of the observations are less than 21?
.60
Let P(A) = 0.6, P(B) = 0.3, and P(A∪B)C = 0.1. Calculate P(A∩B).
0
Peter applied to an accounting firm and a consulting firm. He knows that 30% of similarly qualified applicants receive job offers from the accounting firm, while only 20% of similarly qualified applicants receive job offers from the consulting firm. Assume that receiving an offer from one firm is independent of receiving an offer from the other. What is the probability that both firms offer Peter a job?
0.06
The contingency table below provides frequencies for the preferred type of exercise for people under the age of 35, and those 35 years of age or older. Find the probability that an individual prefers biking given that he or she is 35 years old or older.
0.1698
The mean return on equity (ROE) for a group of firms in an industry is 15% with a variance of 9%. The coefficient of variation of the industry's ROE is __________.
0.2
The contingency table below provides frequencies for the preferred type of exercise for people under the age of 35 and those 35 years of age or older. Find the probability that an individual prefers running and is under 35 years of age.
0.3042
Let P(A) = 0.4, P(B|A) = 0.5, and P(B|Ac) = 0.25. Compute P(B).
0.35
The accompanying table shows students' scores from the final exam in a history course. How many of the students scored at least 70 but less than 90? (HW 2 Q 13)
50
Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000. With the beginning of the next academic year, all professors will get a 2% raise. What will be the average and the standard deviation of their new salaries?
$81,600 and $6,120.
Which of the following variables is categorical?
Gender
The range is defined as __________
MAX-MIN
There is a 25% chance that a customer who purchases milk will also purchase bread. The probability of a milk purchase is 70% and the probability of a bread purchase is 50%. What is the probability that a customer will purchase bread given that he/she buys milk?
36%
Which five values are graphed on a box plot?
Min, Quartile 1, Median, Quartile 3, Max
A sample statistic is an estimate of
population parameter
A company is bidding on two projects, A and B. The probability that the company wins project A is 0.40 and the probability that the company wins project B is 0.25. Winning project A and winning project B are independent events. What is the probability that the company does not win either project?
0.45
Let P(A ^ B)= 0.3 and P(A^B) =0.15 Compute
0.45
Alison has all her money invested in two mutual funds, A and B. She knows that there is a 65% chance that fund A will rise in price, and a 70% chance that fund B will rise in price given that fund A rises in price. What is the probability that both fund A and fund B will rise in price?
0.46
A company is bidding on two projects, A and B. The probability that the company wins project A is 0.40 and the probability that the company wins project B is 0.25. Winning project A and winning project B are independent events. What is the probability that the company wins project A or project B?
0.55
Alison has all her money invested in two mutual funds, A and B. She knows that there is a 40% chance that fund A will rise in price, and a 60% chance that fund B will rise in price given that fund A rises in price. There is also a 20% chance that fund B will rise in price. What is the probability that neither fund will rise in price?
0.64
The following probability table shows probabilities concerning Favorite Subject and Gender. What is the probability of selecting an individual who is a female or prefers science? (HW 4 Q4)
0.750
As of September 30, the earnings per share (EPS) of five firms in the biotechnology industry are 1.53 2.29 2.07 1.69 0.07 The sample mean and the sample standard deviation are the closest to __________
1.53 and 0.87
In the accompanying stem-and-leaf diagram, the values in the stem-and-leaf portions represent 10s and 1s digits, respectively How many values are at least 25 but less than 35?
11
The following histogram represents the number of pages in each book within a collection. What is the frequency of books containing at least 250 but fewer than 400 pages
11
Suppose the data on quiz scores will be grouped into five classes. The width of the classes for a frequency distribution or histogram is the closest to __________. (HW 2 Q 9)
15
A bowler's scores for a sample of seven games were 172 168 188 190 172 182 174 The bowler's modal score is _________
172
Consider a population with data values of 12 8 28 22 12 30 14 The population mean is __________.
18
The price to earnings ratio, also called the P/E ratio of a stock, is a measure of the price of a share relative to the annual net income per share earned by the firm. Suppose the P/Es for a firm's common stock during the past four quarters are 10, 12, 15, and 11, respectively. The standard deviation of the P/E ratio over the four quarters is __________.
2.16
Amounts spent by a sample of 200 customers at a retail store are summarized in the following relative frequency distribution. 0 up to 10/ 15 10 up to 20/ 75 20 up to 30/ 55 30 up to 40 / 55 The mean amount spent by customers is the closest to __________.
22.50
An analyst constructed the following frequency distribution on the monthly returns for 50 selected stocks. The number of stocks with returns of less than 10% is __________. (HW 2 Q 23)
33
A college professor collected data on the number of hours spent by his 100 students over the weekend to prepare for Monday's Business Statistics exam. He processed the data by Excel and the following incomplete output is available. Mean 7 Sample Variance 7.84 Skewness 1.17 The coefficient of variation in the data is __________.
40%
The likelihood of Company A's stock price rising is 20%, and the likelihood of Company B's stock price rising is 30%. Assume that the returns of Company A and Company B stock are independent of each other. The probability that the stock price of at least one of the companies will rise is ______.
44%
The following frequency distribution displays the weekly sales of a certain brand of television at an electronics store. How many weeks of data are included in this frequency distribution? (HW 2 Q 18)
50
Students in Professor Smith's business statistics course have evaluated the overall effectiveness of the professor's instruction on a five-point scale, where a score of 1 indicates very poor performance and a score of 5 indicates outstanding performance. The raw scores are displayed in the accompanying table. What percentage of students gave Professor Smith an evaluation higher than 3? (HW 2 Q 24)
50%
The organization of the Girl Scouts has completed its annual cookie drive. The sales are reported in the accompanying ogive. Approximate the percentage of girls who sold more than 70 boxes of cookies. (HW 2 Q 14)
55%
Total revenue for Apple Computers (in millions) was $42,905 in Year 1, $65,225 in Year 2, and $108,249 in Year 3. The average growth rate of revenue during these three years is the closest to __________.
58.84%
Consider a population with data values of 12 8 28 22 12 30 14 The population variance is the closest to __________.
64.00
The following histogram represents the number of pages in each book within a collection. What is the frequency of books containing at least 250 but fewer than 300 pages?
7
The following data represent the recent sales price (in $1,000s) of 24 homes in a Midwestern city Suppose the data are grouped into five classes, and one of them will be "115 up to 140"—that is, {x; 115 ≤ x < 140}. The relative frequency of this class is __________. (Look at HW 2 Question 4)
7/24
Recent home sales in a suburb of Washington, D.C., are shown in the accompanying ogive. Approximate the percentage of houses that sold for less than $600,000.
80%
The following frequency distribution shows the frequency of the asking price, in thousands of dollars, for current homes on the market in a particular city. What percentage of houses have an asking price under $550,000? (HW2 Q 10)
89.1%
You buy 50 stocks of Company A, 30 of Company B, and 20 of Company C. The annual returns of these companies are 8%, 12%, and 10% respectively. The average return for one year is the closest to __________.
9.6%
The Chief Diversity Officer of an accounting firm wants to make sure gender equity is achieved among all levels of positions of the firm. The Officer has information on an employee's gender, position level, and marital status as shown below: Which of the following methods is best to help determine the firm's status on gender equity?
A contingency table by gender and position level
What type of relationship is indicated in the scatterplot? (HW 2 Q 25)
A positive linear or curvilinear relationship
Which of the following represents a subjective probability?
A skier believes she has a 10% chance of winning a gold medal.
Which of the following methods best describe the relationship between two categorical variables?
A stacked column chart
Given an experiment in which a fair coin is tossed three times, the sample space is S = {HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}. Event A is defined as tossing one head (H). What is the event Ac and what is the probability of this event?
Ac = {TTT, HHT, HTH, THH, HHH}; P(Ac) = 0.625
How does an ogive differ from a polygon?
An ogive is a graphical depiction of a cumulative frequency or cumulative relative frequency distribution, while a polygon is a graphical depiction of a frequency or relative frequency distribution.
Which of the following statements is most accurate when defining percentiles?
Approximately (100 − p)% of the observations are greater than the pth percentile.
Which of the following is the most influenced by outliers?
Arithmetic mean
The accompanying chart shows the number of books written by each author in a collection of cookbooks. What type of chart is this? (HW 2 Q 15)
Bar Chart for Qualitative data
Which of the following represents an empirical probability?
Based on past observation, a manager believes that is a three in five chance of retaining an employee for at least one year.
Population parameters are difficult to calculate due to
Both cost prohibitions on data collection and the infeasibility of collecting data on the entire population
In what way(s) is(are) the concept of geometric mean useful?
Both in evaluating investment returns and in calculating average growth rates
When constructing a frequency distribution for a numerical variable, it is important to remember that __________.
Classes are mutually exclusive
In a marketing class of 60 students, the mean and the standard deviation of scores was 70 and 5, respectively. Use Chebyshev's theorem to determine the number of students who scored less than 60 or more than 80.
at most 15
A professor's rank (assistant, associate, and full), as well as salary, represent ordinal data.
False
Big data is a catchphrase that implies a complete set of population data.
False
Which of the following is an example of quantitative data?
Google's closing stock price today
In inferential statistics, we calculate statistics of sample data to
estimate unknown population parameters and conduct tests about unknown population parameters.
The Fahrenheit scale for measuring temperature would be classified as a(n)
Interval Scale
Which scales of data measurement are associated with quantitative data?
Interval and Ratio
Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000. The salary distribution cannot be regarded as bell-shaped. What can be said about the percentage of salaries that are less than $68,000 or more than or more than $92,000?
It is at most 25%
The owner of a company has recently decided to raise the salary of one employee, who was already making the highest salary, by 20%. Which of the following is(are) expected to be affected by this raise?
Mean Only
In the accompanying stem-and-leaf diagram, the values in the stem-and-leaf portions represent 10s and 1s digits, respectively. The stem-and-leaf diagram shows that the distribution is __________.
Positively Skewed
A recent survey of 200 small firms (annual revenue less than $10 million) asked whether an increase in the minimum wage would cause the firm to decrease capital spending. Possible responses to the survey question were: "Yes," "No," or "Don't Know." This data is best classified as
Nominal Scale
Frequency distributions may be used to describe which of the following types of data?
Nominal, ordinal, and interval data only
Which of the following sets of outcomes described below in I and II represent mutually exclusive events? I. "Your final course grade is an A"; "Your final course grade is a B."II. "Your final course grade is an A"; "Your final course grade is a Pass."
Only I represents mutually exclusive events.
Differences between categories are meaningless with __________ data.
Ordinal
If A and B are independent events, which of the following is correct?
P( A | B) = P(A)
For which of the following data sets will a pie chart be most useful?
Percentage of net sales by product for Lenovo in Year 1
A __________ represents all possible subjects of interest.
Population
The accompanying chart shows the number of books written by each author in a collection of cookbooks. What type of data is being represented?
Qualitative, Nominal
Which of the following is an example of time series data?
Quarterly housing stats collected over the last 60 years
San Francisco 49ers' linebacker Patrick Willis won the Defensive Rookie of the Year Award in 2007 with a total of 174 tackles. Tackles are measured on what kind of a scale? Is a variable measuring the number of tackles considered continuous or discrete?
Ratio Scale: Discrete
Which of the following represents a population and a sample from that population?
Residents of Albany, New York, and registered voters in Albany, New York
You have a point-of-sale data set that provides information on time of sale, products bought, and payment methods customers used to complete their purchases. You want to compare purchases made by cash versus those made by credit card. How should the data be best prepared to make comparisons between the two types of purchases?
Subset the data by method of payment
When some objects are randomly selected, which of the following is true?
The order in which objects are selected does not matter in combinations.
Which of the following is NOT an example of cross-sectional data?
The sales prices of single-family homes in Arizona collected since 2008.
Is it possible for a data set to have no mode?
Yes, if there are no observations that occur more than once.
In its standard form, Chebyshev's theorem provides a lower bound on __________.
the proportion (or percentage) of observations lying within a certain interval
Chebyshev's theorem is applicable when the data are __________.
any shape
The study of statistics is NOT about
the study of mind and consciousness.
Events are collectively exhaustive if _____________.
they contain all outcomes of an experiment
What may NOT be revealed from a scatterplot?
casual relationship between two variables
The intersection of events A and B, denoted by A^ B ___________.
contains outcomes that are both in A and B
An analyst gathered the following information about the net profit margins of companies in two industries: Compared with the other industry, the relative dispersion of net profit margins is smaller for Industry __________. (HW 3 Q10)
it has a smaller coefficient of variation
A college professor collected data on the number of hours spent by his 100 students over the weekend to prepare for Monday's Business Statistics exam. He processed the data by Excel and the following incomplete output is available. Mean 18 Sample Variance 7.11 Skewness 1.05 The median is most likely to be __________.
less than 18 hours
When reading published statistics (numerical facts), you should
only believe those statistics that are adequately supported.
When a characteristic of interest differs among various observations, then it can be termed a
variable
In an experiment in which a coin is tossed twice, which of the following represents mutually exclusive and collectively exhaustive events?
{TT, HH} and {TH, HT}
Which of the following are mutually exclusive events of an experiment in which two coins are tossed?
{TT, HH} and {TH}
For the sample space S = {apple pie, cherry pie, peach pie, pumpkin pie}, what is the complement of A = {pumpkin pie, cherry pie}?
{apple pie, peach pie}
Find the missing values marked xx and yy in the following contingency table. (HW 4 Q 13)
✓ xx = 27, yy = 79
