ECON 3402
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 attributes of a discrete quantitative variable?
It can be used to count items. It can assume only certain values within a range. There are gaps between the values of this variable.
Which of the following statements are true of the weighted mean?
It is a special case of the arithmetic mean. The denominator of the weighted mean is always the sum of the weights. It is used when there are several observations of the same value.
Which one of the following is not a characteristic of a frequency distribution?
It summarizes qualitative data.
Which of the following is true regarding medians and means?
Medians can be calculated from ordinal-level data, but means can't.
What is inferential statistics?
Methods of estimating a property of a population based on a sample.
What information is shown on the horizontal axis of a bar chart?
The qualitative class labels.
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 one of the following is true about pie charts?
The size of a slice should represent the relative frequency or percentage.
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).
A relative frequency distribution shows:
the fraction or percentage of observations in each class interval
Which of the following statements best defines the mode?
the value of the observation that appears most frequently
The mode of a set of data is____________.
the value or values that occur most often
The dispersion of a set of data is often referred to as which of the following?
variation or spread
The median would be a better measure for the center for which of the following data sets?
{9, 11, 14, 16, 1, 12, 15, 17}
Which of the following are disadvantages of the mode?
For many sets of data there is no mode. For many sets of data there are multiple modes.
Which of the following would useful to represent as a frequency table?
Gender of students in a business statistics course. Majors of students in a business statistics course. State of residence of students in a business statistics course.
What does a measure of dispersion tell us about a set of data?
It tells us about the spread of the data.
Which of the following is the best definition of a statistical sample?
a portion, or part, of the population of interest
Which three of the following are not proper and ethical activities for a statistician in working with data?
Use samples that represent only a desired part of a population, Remove outliers that bias the data too far in one direction. Report only those statistics that support his conclusions.
Which one of the following is true regarding raw data?
Raw data are simply a listing of data before summarizing it.
Which of the following are characteristics of raw data?
Raw data can be either qualitative or quantitative When the data is in its original form it is referred to as raw data
Suppose a population is made up of the following values: 1, 8, 5, 6. What is the population mean?
Reason: (1 + 8 + 5 + 6)/4 = 20/4 = 5
The weighted mean provides a way to compute the _____ mean when there are several observations of the same value.
arithmetic
A statistic is:
characteristic of a sample
The two categories of statistical study are:
descriptive statistics and inferential statistics
What are the two types of quantitative variables?
discrete and continuous
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?
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 2k > n.
Which one of the following is a statistic?
mean of a sample
What is another term for the "average" value of a distribution?
measure of location
What is descriptive statistics?
methods of organizing, summarizing, and presenting data in an informative way
Which of the following represent statistical information?
- on average there are 12.5 chocolate chips in a Chips Hello cookie -the median income in Wasau County is $40,578 per year -Lucky's Market sells a maximum of 240 kilograms of apples per month
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
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?"
0.20
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?
10 Reason: (70-1)/7=9.86, round up to 10
What is the range for the following set of data? 3, 5, 4, 6, 7, 10, 9
7
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.
Regarding frequency tables and frequency distributions, which one of the following is true?
Both show the number of observations in each class.
What is the final step in creating a frequency distribution?
Count the number of observations in each class.
For which of the following variables can one calculate a median?
Daily temperatures in August for the past 10 years Shoe size Finishing position in a marathon (1st, 2nd, 3rd, ...)
For which of the following variables can one calculate an arithmetic mean?
Daily temperatures in August for the past 10 years Time to run a marathon
The nominal level of data describes what type of information?
Observations of a qualitative variable that can only be classified and counted.
Regarding frequency tables and frequency distributions, which of the following are true?
Only frequency tables use qualitative data. Both use mutually exclusive classes.
Which one of the following is true regarding the use of the mode, mean, and median for different levels of measurement?
Only the mode can be used for nominal-level data.
Which of the following are characteristics of frequency distributions?
Organize raw data Use classes and frequencies to organize data It provides the tally for each class.
What level of data is represented by the ages of patients in a local hospital?
Ratio
Which of the following is classified as ordinal-level data?
Someone's ranking of their three favorite foods.
Which one of the following are properties of ordinal-level data?
The data can be ranked or counted.
Which of the following best describes interval-level data?
The distance between values is a known unit of measure.
Which of the following is the best definition of a statistical population?
The entire set of individuals, objects or measurements of interest.
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.
What is the purpose of a measure of location?
To indicate the center of a distribution of data.
Which of the following are the four levels of measurement possible for data?
Interval level Ordinal-level Nominal-level Ratio-level
Which of the following kinds of data can be used to find a median value?
Interval level data Ratio level data Ordinal level data
The mean, median, and mode are all the same for which type of distribution?
symmetrical distribution
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
Which of the following variables is recorded at the interval level of measurement?
A man's shoe size.
Identify all of the following items which are qualitative variables.
A person's favorite food type. The colors in a package of M&M's. The species of trees in a park.
Which of the following is the best definition of "class midpoint"?
Halfway between the lower or upper limits of two consecutive classes.
Which of the following best describes the role of a statistician in working with data?
He should strive to present his analysis with clarity, honesty, and integrity.
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.
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 library.
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.
The variance is a measure of central tendency.
False
Descriptive statistics uses the data to make inferences and predictions about a population based on a sample of data taken from the population in question.
False because inferential statistics makes predictions about a population based on a sample of data taken from the population.
Which of the following are important properties of the arithmetic mean?
All of the values in the data are used in calculating the mean. Σ(X-X)=0 i.e. the sum of the deviations is zero. There is only one mean for a set of data.
Which of the following are characteristics of bar charts?
Bar charts are used for qualitative data. Plotted rectangles should be the same width. There should be gaps between bars.
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.
The _______ of a set of data is the value or values that occur most often.
Mode
Most of the used cars sold by a used car dealer are priced at about $16,000. The median price of a car on the lot is $14,450 but a few sell for under $2000. The distribution of car prices is:
negatively skewed
What characteristic of a data set makes the median the better measure of the center of the data than the mean?
When the data set includes one or two very large or very small values.
The median is defined as:
the midpoint of the values after they have been arranged in rank order
How does the formula for the sample mean differ from the formula for population mean?
The formulas are functionally the same, but 'n' (the sample size) is used instead of 'N' (the population size).
Which one of the following is true for a symmetrical distribution?
The mean, median and mode all have the same value.
Which of the following accurately describes the median of a set of data?
The midpoint of the data when it is arranged in order.
Which of the following are used to measure dispersion?
Variance Standard Deviation Range
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.
The mode can be computed for which of the following levels of data?
nominal, ordinal, interval, ratio
Which level of data gives the most information about the observation?
ratio
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.
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 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.
Which of the following variables is recorded at the ratio level of measurement?
Salaries of business school graduates.
How do you find the Population Mean for a set of data?
Sum the values in the population and then divide by the number of values in the population.
Why would the median be a better measure of the center than the mean for the following set of data? 3, 4, 4, 4, 5, 6, 7, 23
The number 23 is much larger than the other numbers and would unduly influence the mean.
Which of the following are discrete variables?
The number of cars for sale on a used car lot. The number of customers using an ATM on a given day.
Which of the following examples are statistics? Select all that apply.
The number of home runs in last year's World Series. Yesterday's share price for Proctor and Gamble stocks. The median price of a house in Detroit.
Which one of the following is true for a negatively skewed distribution?
There are a small number of observations that are much lower in value than most of the data.
What does N represent in the formula for the population variance?
number of observations in a population
When you calculate the sample mean, you divide the sum of the values in the sample by
number of values in a sample
What level of data is represented by the fire risk (Low, Moderate, High or Severe) today in Arapahoe National Forest?
ordinal
