BUSI 230 - FINAL Terminology Practice
Select three examples of data sets that do not have inherent zeros below.
(1) A student's level of happiness measured from 0 to 10 (2) Average IQ score of a high school class (3) Temperature in degrees Farenheit
Select three examples of data sets that have inherent zeros below.
(1) Average age of college students in years (2) Maximum wind speed during a hurricane (3) Average monthly precipitation in inches
Choose the three formulas that can be used to describe complementary events.
(1) P(E) = 1 - P(E') (2) P(E') = 1 - P(E) (3) P(E) + P(E') = 1
Determine which numbers could be used to represent the probability of an event.
(a) (15/15), because probability values can equal 1. (b) 0, because probability values can equal 0.
The following appear on a physician's intake form. Identify the level of measurement of the data. (a) Height (b) Pain level (scale of 0 to 10) (c) Family history of illness (d) Year of birth
(a) Ratio (b) Ordinal (c) Nominal (d) Interval
For the same sample statistics, which level of confidence would produce the widest confidence interval? Explain your reasoning.
99%, because as the level of confidence increases, z꜀ increases.
What is the difference between a census and a sampling?
A census includes the entire population. A sampling includes only part of the population.
What is a discrete probability distribution? Choose the correct answer below.
A discrete probability distribution lists each possible value a random variable can assume, together with its probability.
What is the difference between a frequency polygon and an ogive?
A frequency polygon displays class frequencies while an ogive displays cumulative frequencies.
What is the difference between a parameter and a statistic?
A parameter is a numerical description of a population characteristic. A statistic is a numerical description of a sample characteristic.
How is a sample related to a population?
A sample is a subset of a population.
What is an inherent zero? Describe three examples of data sets that have inherent zeros and three that do not.
An inherent zero is a zero that implies none.
What is the difference between an outcome and an event?
An outcome is the result of a single probability experiment. An event is a set of one or more possible outcomes.
What is a similarity between the Empirical Rule and Chebychev's Theorem?
Both estimate proportions of the data contained within k standard deviations of the mean.
What is the difference between class limits and class boundaries?
Class limits are the least and greatest numbers that can belong to the class. Class boundaries are the numbers that separate classes without forming gaps between them. For integer data, the corresponding class limits and class boundaries differ by 0.5.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. A population is the collection of some outcomes, responses, measurements, or counts that are of interest.
False. A population is the collection of all outcomes, responses, measurements, or counts that are of interest.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. A statistic is a measure that describes a population characteristic.
False. A statistic is a measure that describes a sample characteristic.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. Data at the ordinal level are quantitative only.
False. Data at the ordinal level can be qualitative or quantitative.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. In a frequency distribution, the class width is the distance between the lower and upper limits of a class.
False. In a frequency distribution, the class width is the distance between the lower or upper limits of consecutive classes.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. More types of calculations can be performed with data at the nominal level than with data at the interval level.
False. More types of calculations can be performed with data at the interval level than with data at the nominal level.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. The method for selecting a stratified sample is to order a population in some way and then select members of the population at regular intervals.
False. The method for selecting a systematic sample is to order a population in some way and then select members of the population at regular intervals.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. The second quartile is the mean of an ordered data set.
False. The second quartile is the median of an ordered data set.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. Using a systematic sample guarantees that members of each group within a population will be sampled.
False. Using a stratified sample guarantees that members of each group within a population will be sampled.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. If two events are independent, P(A B) = P(B).
False; if events A and B are independent, then P(A and B) = P(A) * P(B).
Name some ways to display quantitative data graphically. Select all that apply.
Histograms, Scatter plots, Dot plots, Time series plots, Stem-and-leaf plots
What is the difference between an observational study and an experiment?
In an experiment, a treatment is applied to part of a population and responses are observed. In an observational study, a researcher measures characteristics of interest of a part of a population but does not change existing conditions.
The years that your college football team won a scholarship are shown below. 1952, 1975, 1983, 1988, 1989, 1992, 1998, 2011, 2012 Determine the level of measurement of the data set. Explain your reasoning.
Interval. The data can be ordered and difference between data entries are meaningful, but a zero entry is not an inherent zero.
What is an advantage of using the range as a measure of variation?
It is easy to compute.
What does the mean of a probability distribution represent?
It is the expected value of a discrete random variable.
Why is a sample used more often than a population?
It is usually impossible to count the entire population.
What is a disadvantage of using the range as a measure of variation?
It uses only two entries from the data set.
From a random sample of 46 business days, gold prices had a mean of $1383.85 . Assume the population standard deviation is $202.30 . This creates a 90% confidence interval for the population mean of left parenthesis $1334.79 comma $1432.91 right parenthesis. Does it seem possible that the population mean could equal the sample mean exactly? Explain.
It would be very unlikely because the margin of error is large enough that the odds of selecting an exact value is very low.
Determine if the survey question is biased. If the question is biased, suggest a better wording. How often do you eat fast food during an average month?
No, because it does not lead the respondent to any particular answer.
Name each level of measurement for which data can be qualitative.
Ordinal, Nominal
If two events are mutually exclusive, why is P(A and B) = 0?
P(A and B) = 0 because A and B cannot occur at the same time.
Name some ways to display qualitative data graphically. Select all that apply.
Pareto charts, Pie charts, Bar graphs
Decide if the situation involves permutations, combinations, or neither. Explain your reasoning. The number of ways 13 people can line up in a row for concert tickets.
Permutations. The order of the 13 people in line matters.
Describe the relationship between quartiles and percentiles.
Quartiles are special cases of percentiles. Q(sub1) is the 25th percentile, Q(sub2) is the 50th percentile, and Q(sub3) is the 75 percentile.
Name each level of measurement for which data can be quantitative.
Ratio, Ordinal, Interval
What is the difference between relative frequency and cumulative frequency?
Relative frequency of a class is the percentage of the data that falls in that class, while cumulative frequency of a class is the sum of the frequencies of that class and all previous classes.
What is replication in an experiment? Why is replication important?
Replication is repetition of an experiment under the same or similar conditions. Replication is important because it enhances the validity of the results.
What do you do when you have to find the Z-Score of a given area, and a percentage or a P(value) is given to you for finding the probability (the probability that you need to use for the inverse function)?r
Take the percentage or value and divide by 100, and you will be left with your probability.
What is a difference between the Empirical Rule and Chebychev's Theorem?
The Empirical Rule assumes the distribution is aproximately symmetric and bell-shaped and Chebychev's Theorem makes no assumptions.
How is a Pareto chart different from a standard vertical bar graph?
The bars are positioned in order of decreasing height with the tallest bar on the left.
Explain how the complement can be used to find the probability of getting at least one item of a particular type.
The complement of "at least one" is "none." So, the probability of getting at least one item is equal to 1 - P(none of the items).
Determine whether the data set is a population or a sample. Explain your reasoning. The amount of energy collected from every solar panel on a photovoltaic power plant
The data set is a population because it is a collection of the energy collected from all of the solar panels on a photovoltaic power plant.
What must be known about a data set before the Empirical Rule can be used?
The distribution must be approximately symmetric and bell-shaped.
Decide whether the events shown in the accompanying Venn diagram are mutually exclusive. Explain your reasoning.
The events are mutually exclusive, since there is at least 1 presidential candidate who won the state of Montana and lost the election.
A study of 881 senior citizens shows that participants who exercise regularly exhibit less of a decline in the cognitive ability than those who barely exercise at all. From this study, a researcher infers that your cognitive ability increases the more you exercise. What is wrong with this type of reasoning?
The inference may incorrectly imply that exercise increases a person's cognitive ability. The study shows a slower decline in cognitive ability.
Explain how the interquartile range of a data set can be used to identify outliers.
The interquartile range (IQR) of a data set can be used to identify outliers because data values that are greater than Q(sub3) + 1.5(IQR) or less than Q(sub1) - 1.5(IQR) are considered outliers.
What does the value µ mean?
The mean of the population data set.
What does the value x̄ mean?
The mean of the sample data set.
What does the value N mean?
The number of values in the population data set.
What does the value n mean?
The number of values in the sample data set.
What are the two conditions that determine a probability distribution? Choose the correct answer below.
The probability of each value of the discrete random variable is between 0 and 1, inclusive, and the sum of all the probabilities is 1.
Determine whether the following problem involves a permutation or a combination and explain your answer. How many different 2-letter passwords can be formed from the letters O, P, Q, R, S, T, and U if no repetition of letter is allowed?
The problem involves a permutation because the order in which the letters are selected does matter.
Determine whether the survey question is biased. If the question is biased, suggest a better wording. How does the media influence the opinions of voters?
The question is biased because it already suggests that the media influences the opinions of voters. The question could be rewritten as "Does the media influence the opinions of voters? If so, how?"
Determine if the survey question is biased. If the question is biased, suggest a better wording. Why is eating vegetables good for you?
The question is biased. The wording "How do you think eating vegetables affects your health?" would be better.
Determine whether the random variable x is discrete or continuous. Explain. Let x represent the weight of a T-bone steak.
The random variable is continuous, because it has an uncountable number of possible outcomes.
Explain how to find the range of a data set. Choose the correct answer below.
The range is found by subtracting the minimum data entry from the maximum data entry.
What does the value σ mean?
The spread of the data from the population mean.
What does the value s mean?
The spread of the data from the sample mean.
Explain the relationship between variance and standard deviation. Can either of these measures be negative? Explain.
The standard deviation is the positive square root of the variance. The standard deviation and variance can never be negative. Squared deviations can never be negative.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. A placebo is an actual treatment.
The statement is false. A placebo is a fake treatment.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. A sample statistic will not change from sample to sample.
The statement is false. A sample statistic can change from sample to sample.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. For data at the interval level, you cannot calculate meaningful differences between data entries.
The statement is false. A true statement is "For data at the interval level, you can calculate meaningful differences between data entries."
Determine whether the statement below is true or false. If it is false, rewrite it as a true statement. A combination is an ordered arrangement of objects.
The statement is false. A true statement would be "A permutation is an ordered arrangement of objects."
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. It is impossible to have a z-score of 0.
The statement is false. A z-score of 0 is a standardized value that is equal to the mean.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. A double-blind experiment is used to increase the placebo effect.
The statement is false. Double blinding is used to decrease the placebo effect.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. Inferential statistics involves using a population to draw a conclusion about a corresponding sample.
The statement is false. Inferential statistics involves using a sample to draw a conclusion about a corresponding population.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. You toss a fair coin nine times and it lands tails up each time. The probability it will land heads up on the tenth flip is greater than 0.5.
The statement is false. The correct statement is "You toss a fair coin nine times and it lands tails up each time. The probability it will land heads up on the tenth flip is exactly 0.5."
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. A graph of the cumulative frequencies can decrease from left to right.
The statement is false. The graph of cumulative frequencies always starts at the lower boundary of the first class and increases to the upper boundary of the last class, and therefore always increases from left to right.
Determine if the statement is true or false. If it is false, rewrite it as a true statement. It is impossible for the Census Bureau to obtain all the census data about the population of the United States.
The statement is true.
Determine whether the statement below is true or false. If it is false, rewrite it as a true statement. When you divide the number of permutations of 11 objects taken 3 at a time by 3!, you will get the number of combinations of 11 objects taken 3 at a time.
The statement is true.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. The difference between two consecutive midpoints is equal to the class width.
The statement is true. The midpoint is the sum of the lower and upper limits of the class divided by two. The distance between two consecutive lower (or upper) class limits is equal to the class width.
Determine whether the study is an observational study or an experiment. Explain. To study the effects of music on body image, researchers played a song with a body-positive message or a song with a body-negative message to different groups of people.
The study is an experiment, because it applies a treatment to the people.
Determine whether the study is an observational study or an experiment. Explain. A research study compared the memory retention of subjects when a learning activity was followed by a brief period of wakeful rest and when a learning activity was followed by a brief period of distraction.
The study is an experiment, because it applies a treatment to the subjects.
Determine whether the study is an observational study or an experiment. Explain. In a survey of U.S. employees, 41.8 % of black women say they are uncomfortable sharing thoughts about racial inequality.
The study is observational, because it does not apply a treatment to the employees.
The length of a guest lecturer's talk represents the third quartile for talks in a guest lecture series. Make an observation about the length of the talk.
The talk is longer in length than 75% of the lectures in the series.
For the given pair of events, classify the two events as independent or dependent. Randomly selecting a customer at the movies Randomly selecting a customer eating popcorn
The two events are dependent because the occurrence of one affects the probability of the occurrence of the other.
A study found that people who suffer from obstructive sleep apnea are at increased risk of having heart disease. Identify the two events described in the study. Do the results indicate that the events are independent or dependent?
The two events are sleep apnea and heart disease. Both events are independent of each other.
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Favorite musical band
The variable is qualitative because a favorite musical band describes an attribute of characteristic.
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Color of car driven
The variable is qualitative because color describes an attribute or characteristic.
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Gender of children born in a maternity ward
The variable is qualitative because genders are attributes or labels.
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Case ID numbers at a law firm
The variable is qualitative because identification numbers are attributes or labels.
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Favorite types of food
The variable is qualitative because types are attributes or labels.
Determine whether the following events are mutually exclusive. Explain your reasoning. Event A: Randomly select a voter who legally voted for the President in California. Event B: Randomly select a voter who legally voted for the President in Delaware.
These events are mutually exclusive, since it is not possible for a voter to both have legally voted for the President in California and have legally voted for the President in Delaware.
Determine whether the following events are mutually exclusive. Explain your reasoning. Event A: Randomly select a male mathematics major. Event B: Randomly select a mathematics major who is 21 yrs old.
These events are not mutually exclusive, since it is possible to select a male mathematics major who is 21 years old.
A motorcycle's fuel efficiency represents the ninth decile of vehicles in its class. Make an observation about the motorcycle's fuel efficiency.
The motorcycle's fuel efficiency is greater than the fuel efficiency for 90% of vehicles in its class.
A student's grade on the Fundamentals of Engineering exam has a z-score of -0.5. Make an observation about the student's grade.
The student's grade on the exam was below the average.
Determine whether the statement is true or false. If it is false rewrite it as a true statement An outlier is any number above Q(sub3) or below Q(sub1).
This statement is false. A true statement is "An outlier is any number above Q(sub3) + 1.5(IQR) or below Q(sub1) - 1.5(IQR) are considered outliers."
As the size of a sample increases, the standard deviation of the distribution of sample means increases.
This statement is false. A true statement is, "As the size of a sample increases, the standard deviation of the distribution of sample means decreases."
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. If two events are mutually exclusive, they have no outcomes in common.
True
Describe the difference between the calculation of population standard deviation and that of sample standard deviation.
When calculating the population standard deviation, the sum of the squared deviation is divided by N, then the square root of the result is taken. When calculating the sample standard deviation, the sum of the squared deviations is divided by n - 1, then the square root of the result is taken.
Given a data set, how do you know whether to calculate sigma or s?
When given a data set, one would have to determine if it represented the population or if it was a sample taken from the population. If the data are a population, then is population standard deviation calculated. If the data are a sample, then s is calculated.
When estimating a population mean, are you more likely to be correct when you use a point estimate or an interval estimate? Explain your reasoning.
You are more likely to be correct using an interval estimate because it is unlikely that a point estimate will exactly equal the population mean.
As the size of a sample __________, the standard deviation of the distribution of sample means __________.
increases, decreases
Determine whether the statement is true or false. You are taking a test that has true or false and multiple choice questions. The event "choosing false on a true or false question and choosing A or B on a multiple choice question" is a simple event.
False, the event is not simple because it consists of two possible outcomes.
Determine whether the data set is a population or a sample. Explain your reasoning. The diastolic blood pressure of 10 patients in a hospital containing 200 patients
Sample, because the collection of 10 patients' blood pressures is a subset of all patients in the hospital.
