MBA 513 mod 1 ch1&2

Suppose a frequency distribution has the following consecutive classes: $20 up to $30 $30 up to $40 $40 up to $50 What is the class midpoint for the first class?

$25

What are the two types of quantitative variables?

Discrete and Continuous.

Raw data can be either __________ or ____________ -When the data is in its original form it is referred to as _____ _______

qualitative or quantitative raw data

Data that can be measured using a continuous variable.

ratio

A relative frequency distribution shows:

the fraction or percentage of observations in each class interval

Inferential statistics makes predictions about a population based on a sample of data taken from the population.

true

Statistics is about collecting and processing information to provide a basis for decision making.

true

True or false: Statistics knowledge is necessary to successfully use business analytics.

true

The mode of a set of data is the _________ that occur most often

value or values

What level of data is represented by the fire risk (Low, Moderate, High or Severe) today in Arapahoe National Forest?

Ordinal

Which of the following variables is recorded at the ratio level of measurement?

Salaries of business school graduates.

Which one of the following are properties of ordinal-level data?

The data can be ranked or counted.

Which of the following operations is true regarding relative frequency distributions?

The relative frequency is found by dividing the class frequencies by the total number of observations.

Which of the following best describes the role of a statistician in working with data?

The statistician should strive to present analysis with clarity, honesty, and integrity.

Which of the following is classified as ordinal-level data?

Someone's ranking of their three favorite foods. REASON: because it has an ~order~

Identify which one of the following is a continuous quantitative variable. -The average weight of apples in a box at the market. -The number of trees in Central Park. -The number of classes a student is taking. -The number of holidays in a year.

The average weight of apples in a box at the market. reason: -The number of trees in Central Park. -The number of classes a student is taking. -The number of holidays in a year. (these variables can assume only certain values.)

In using the "2 to the k rule" to determine the number of classes for a frequency distribution, what is the meaning of the variable k? Multiple choice question.

k is the smallest number of classes such that 2k is greater than the number of observations.

A useful way to determine the number of classes (k) in a frequency distribution of n items is the "2 to the k rule". Which of the following correctly describes this rule?

k is the smallest number such that 2^k > n.

The ______________ of a set of data is the value or values that occur most often.

mode

Data that can be ranked in order.

ordinal

Which level of data gives the most information about the observation?

Ratio

Which one of the following is true regarding raw data?

Raw data is simply a listing of data before summarizing it.

What is the final step in creating a frequency distribution?

Count the number of observations in each class.

What is inferential statistics?

Methods of estimating a property of a population based on a sample.

Regarding frequency tables and frequency distributions, which of the following are true?

-Both use mutually exclusive classes. -Only frequency tables use qualitative data.

Which of the following are examples of descriptive statistics? -Calculating summary measures of the prices of houses sold in Las Vegas in January. -Creating a pie chart to show majors of students in your business statistics class. -Sampling voters to see who is going to win an election. -Checking the price a camera at four stores to estimate its average sale price.

-Calculating summary measures of the prices of houses sold in Las Vegas in January. -Creating a pie chart to show majors of students in your business statistics class. REASON: -Sampling voters to see who is going to win an election. AND -Checking the price a camera at four stores to estimate its average sale price. ARE INFERENTIAL STATISTICS

Suppose that the miles per gallon for 80 cars is summarized in a frequency distribution. Below is a part of the distribution. What would the relative frequency be for the class "20 up to 24?" MPG: 16 up to 20 and Frequency: 10 MPG: 20 up to 24 and Frequency: 16

0.20 reason 16 / 80 = .20

Place the following steps used in constructing a frequency distribution in the correct order, with the first step being on the top.

1. decide on the number of classes 2. determine the class interval 3. set individual class limits 4. tally the number of observations in each class

Suppose you are trying to summarize a data set with a maximum value of 70 and a minimum value of 1. If you have decided to use seven classes, which one of the following would be a reasonable class interval? Multiple choice question.

10 Reason: (70-1)/7=9.86, round up to 10

Given below are the data for blood types: A B B AB O O O B AB B A B 0 O O A O A A 0 A B B 0 AB Which is the frequency for blood type AB?

3 (it occurs 3 times)

How does statistics help us understand large amounts of numerical information?

A good working knowledge of statistics is useful to organize and summarize information.

Identify all of the following items which are qualitative variables.

A person's favorite food type. The species of trees in a park. The colors in a package of M&M's reason: these are NOT numbers so they are QUALITATIVE

Which of the following is not a useful practice in setting individual class limits for a frequency distribution?

Excluding outliers that cause the interval to be too wide.

A frequency distribution table shows the number of observations for each class interval of data. How is this data plotted as a frequency polygon?

Frequency is plotted on the vertical axis and the class midpoint is plotted on the horizontal axis.

Which of the following is an advantage of a frequency polygon over a histogram?

It allows comparing directly two or more frequency distributions.

Which of the following features is an advantage that the frequency polygon has over the histogram?

It can directly compare two or more frequency distributions.

Which of the following is an advantage of a cumulative frequency polygon over a histogram or frequency polygon?

It can show the total number of observations less than a particular class' upper limit

Which one of the following is not a characteristic of a frequency distribution? -It summarizes qualitative data. -It uses mutually exclusive classes. -It uses collectively exhaustive classes. -It displays the number of observations in each class.

It summarizes qualitative data.

What is descriptive statistics?

Methods of organizing, summarizing, and presenting data in an informative way.

What level of data is represented by the genres of music played by different radio stations?

Nominal

Which of the following are the four levels of measurement possible for data? NIOR

Nominal-level Interval level Ordinal-level Ratio-level

The nominal level of data describes what type of information?

Observations of a qualitative variable that can only be classified and counted.

Halfway between the lower or upper limits of two consecutive classes.

class midpoint

Which of the following are attributes of a discrete quantitative variable?

-It can assume only certain values within a range. -It can be used to count items. -There are gaps between the values of this variable.

Which of the following are discrete variables? -The number of customers using an ATM on a given day. -The number of cars for sale on a used car lot. -The height of trees in Central Park. -The amount of time a student studied for a test.

-The number of customers using an ATM on a given day. -The number of cars for sale on a used car lot.

Which of the following examples are statistics?

-The number of home runs in last year's World Series. -The median price of a house in Detroit. -Yesterday's share price for Proctor and Gamble stocks. (any numerical info)

What information is shown on the horizontal axis of a bar chart?

-The qualitative class labels. reason: The number of observations in each class (This is shown on the vertical axis.)

Identify all of the following items which are quantitative variables.

-The weight of a Siamese cat. -The miles per gallon for a particular model of car.

Which of the following are characteristics of frequency distributions?

-Use classes and frequencies to organize data -Organize raw data -It provides the tally for each class.

Which of the following variables is recorded at the interval level of measurement? -a mans shoe size -The publisher of a textbook. -A student's class rank. -Number of patients visiting the ER today.

-a mans shoe size reason: -The publisher of a textbook. (categorical data.) -A student's class rank. (ranked data) -Number of patients visiting the ER today. (This is numerical data with a meaningful 0.)

Which is the best definition of a quantitative variable?

A variable that can be reported numerically

Which one of the following is a population in the statistical sense? -All of the automobiles sold in Canada in 2016. -The amount purchased by every 25th customer at Best Buy on Saturday. -Every eighth person on the class roster. -A handful of jelly beans from a jar of mixed flavors.

All of the automobiles sold in Canada in 2016. reason: -The amount purchased by every 25th customer at Best Buy on Saturday. (This is not a population because it does not include the entire set of customers on Saturday.) -Every eighth person on the class roster. (example of a sample) -A handful of jelly beans from a jar of mixed flavors. (example of sample of the jelly beans in the jar.)

Regarding frequency tables and frequency distributions, which one of the following is true?

Both show the number of observations in each class.

Which of the following represents data recorded at the nominal level?

Brand of newly purchased TV.

Which best describes the purpose of business analytics?

Business analytics is used to process and analyze data and information to support a story or narrative of a company's business.

How has technology increased the need for statistical analysis?

Vast amounts of data are collected, and understanding it requires statistical knowledge.

for pie charts, the size of a slice should represent the relative frequency or ___________

percentage

Which of the following are reasons to study statistics?

-Data is collected everywhere, and statistics is needed to translate that data into useful information. -Statistical knowledge is needed to understand the world and be conversant in your career. -Statistics are used to make personal and professional decisions

Which of the following are characteristics of frequency tables?

-No observation can fit into more than one class. -They can be used for qualitative data.

Identify all of the following items which are quantitative variables. -The miles per gallon for a particular model of car. -The weight of a Siamese cat. -The color of a person's eyes. The major of a college graduate.

-The miles per gallon for a particular model of car. -The weight of a Siamese cat. (numerical info) reason: -The color of a person's eyes. The major of a college graduate. (not a number)

Which of the following best describes interval-level data?

The distance between values is a known unit of measure.

Histograms are used to display properties of quantitative variables. (interval or ratio level) Which of the following features is not part of a histogram?

The frequency of occurrence of a nominal variable.

A business statistics course has 2 accounting majors, 4 finance majors, 6 marketing majors, and 8 insurance majors. Which one of the following is true if a pie chart was constructed to depict majors of students?

The marketing slice would be three times as big as the accounting slice.

Which of the following is a feature of a relative frequency distribution?

The sum of the relative frequencies must be one (assuming no rounding errors).

In a frequency polygon the points are plotted at the intersection of the class frequencies and the:

class midpoints

The value shown on the vertical axis of a cumulative frequency polygon for a particular class is found by:

counting the number of observations less than the upper limit of the class

The two categories of statistical study are:

descriptive statistics and inferential statistics

Which of the following are example of inferential statistics? -Estimating the average weight in a box of apples by measuring the weight of five apples. -Counting the blue candies in a package of M&M's as a way to estimate the proportion of blue candies in all packages. -Making a bar chart from a set of data.

-Estimating the average weight in a box of apples by measuring the weight of five apples. -Counting the blue candies in a package of M&M's as a way to estimate the proportion of blue candies in all packages. reason: -Making a bar chart from a set of data. (This is an example of descriptive statistics.) -Placing the prices of houses for sale in April in Boston in rank order. (This is an example of descriptive statistics)

Which of the following are attributes of a continuous quantitative variable?

-It is typically the result of measuring something. -It can take on any value within a range of values. -There are no required gaps between values.

Which three of the following are samples in the statistical sense? -Every eighth person on the class roster. -Ten apples selected from a grocery store bin containing 100 apples. -Six randomly chosen books from the libra -In a study of students at the University of Iowa, all of the enrolled students.

-Every eighth person on the class roster. -Ten apples selected from a grocery store bin containing 100 apples. -Six randomly chosen books from the libra reason: In a study of students at the University of Iowa, all of the enrolled students. (When all the members of a defined set are included, it is a population.)

Which one of the following is not a characteristic of a frequency distribution? -It summarizes qualitative data. -It displays the number of observations in each class. -It uses collectively exhaustive classes. -It uses mutually exclusive classes.

-It summarizes qualitative data.

Which of the following are characteristics of bar charts? -Plotted rectangles should be the same width. -Bar charts are used for qualitative data. -There should be gaps between bars. -Plotted rectangles should be the same height.

-Plotted rectangles should be the same width. -Bar charts are used for qualitative data. -There should be gaps between bars. reason: Plotted rectangles should be the same height. (The height should match the class frequency.)

Which three of the following are not proper and ethical activities for a statistician in working with data?

-Remove outliers that bias the data too far in one direction. -Use samples that represent only a desired part of a population. -Report only those statistics that support his conclusions.

Which of the following are examples of how organizations use statistics?

-Retailers use product purchase data to manage the distribution of products and make marketing and sales decisions. -Google uses search engine data records to prioritize results for future searches.

Which of the following is the best definition of a statistical sample? -A portion, or part of the population of interest. -The entire set of individuals or objects or measurements of interest. -A random selection of 20 people to buy coffee at Mike's on Friday. -The arithmetic mean of a set of measurements.

A portion, or part of the population of interest. REASON: -The entire set of individuals or objects or measurements of interest. (This is the definition of a population) -A random selection of 20 people to buy coffee at Mike's on Friday. (This is a sample of coffee drinkers, but not a definition.) -The arithmetic mean of a set of measurements. (This is a statistic.)

Observations of a quantitative variable where differences between measures are constant in size.

nominal

Which of the following practices are commonly used in setting class limits for a frequency distribution?

-Rounding the class size up. -Placing "excess" interval width equally in the two tails of the distribution.

CH2 Which of the following would be useful to represent as a frequency table? -State of residence of students in a business statistics course. -Majors of students in a business statistics course. -Gender of students in a business statistics course. -Age of students in a business statistics course.

-State of residence of students in a business statistics course. -Majors of students in a business statistics course. -Gender of students in a business statistics course. reason: Age of students in a business statistics course. (Age is a quantitative variable)

Which of the following is the best definition of a statistical population? -The entire set of individuals, objects or measurements of interest. -A portion or part of a set of objects or measures of interest. -The set of all types of statistics that can be listed for a group of individuals or objects -The number of people living in a particular city.

-The entire set of individuals, objects or measurements of interest. Reason: -The number of people living in a particular city. (demographic population)

Which of the following represent statistical information? -The median income in Wasau County is $40,578 per year. -On average there are 12.5 chocolate chips in a Chips Hello cookie. -Lucky's Market sells a maximum of 240 kilograms of apples per month. -The average poodle is larger than the average setter.

-The median income in Wasau County is $40,578 per year. -On average there are 12.5 chocolate chips in a Chips Hello cookie. -Lucky's Market sells a maximum of 240 kilograms of apples per month. REASON: The average poodle is larger than the average setter. (NOT NUMERICAL INFO)

Which of the following are properties of ratio-level data?

-The ratio between two measures is meaningful. -It has all the properties of interval-level data. -The zero point of the data is meaningful.

Which of the following can be observed from a histogram?

-The spread of the data. -The shape of the distribution. -The approximate number of observations.

Which of the following is not part of the science of statistics? Interpreting data to assist in decision making. Collecting and organizing data. Analyzing data. Presenting data in a clear way. Choosing data that supports your conclusion.

Choosing data that supports your conclusion.