BAN chapter 1 study questions

A useful way of comparing the distribution of a numerical variable across categories of some categorical variable is with a. side-by-side box plot b. side-by-side pivot table c. both of these options d. neither of these options.

c. both of these options

A scatterplot allows one to see a. what type of relationship there is between two variables b. whether there is any relationship between two variables c. both options are correct d. neither option is correct.

c. both options are correct

We can infer that there is a strong relationship between two numerical variables when: a. the points on a scatterplot cluster-tightly around an upward sloping straight line b. the points on a scatterplot cluster tightly around a downward sloping straight line. c. either of these options d. neither of these options.

c. either of these options

The decision making process includes: a. optimization techniques for problems with no uncertainty b. decision analysis for problems with uncertainty c. structured sensitivity analysis d. All of these choices

d. All of these choices

Which of the following is not one of the important themes of your Data Analysis & Decision Making Book?

data mining

Which of the following is not one of the important themes of your Data Analysis & Decision Making book?

data mining

one reason for standardizing random variables is to measure variables with:

different means and standard deviation on a single scale.

How is the median defined if the number of observations is even?

the average of the two middle observations

A population includes all elements or objects of interest in a study, whereas a sample is a subset of the population used to gain insights into the characteristics of the population.

true

If the mean is 75 and two observations have values of 65 and 85, what is the squared deviation of each?

100

A sample of 20 observations has a standard deviation of 4. The sum of the squared deviations from the sample mean is:

304

Gender and State are examples of which type of data?

Categorical data.

All nominal data may be treated as ordinal data.

False

Correlation can be affected by the measurement scales applied to X and Y variables.

False

The median is one of the most frequently used measures of variability.

False

What measure distribution relates to extreme events, such as stock market cash?

Kurtosis

A distribution of a numerical variable with no skewness is said to be symmetric.

True

A frequency table indicates how many observations fall within each category, and a histogram is its graphical analog.

True

A histogram is based on binning the variable, which means putting the variable into discrete categories.

True

A random variable X is normally distributed with a mean of 175 and a standard deviation of 50. Given that X= 150, its corresponding Z-score is -0.50.

True

Abby has been keeping track of what she spends to rent movies. The last seven weeks expenditures in dollars were 6,4,8,9,12 and 4. The mean amount Abby spends on renting movies is $7

True

Age, height, and weight are examples of numerical data.

True

Both ordinal and nominal variables are categorical.

True

Statisticians often refer to the pivot tables that display counts as contingency tables or cross tabs.

True

The Poisson distribution is applied to events for which the probability of occurrence over a given span of time, space, or distance is very small.

True

The number of loan defaults per month at a bank is Poisson distributed.

True

The scatterplot is a graphical technique used to make apparent the relationship between two numerical variables.

True

The total area under the normal distribution curve is equal to one

True

The normal distribution is:

continuous distribution with two parameters

Researchers may gain insight into the characteristics of a population by examining a

d. sample of the population

The binomial probability distribution is used with:

discrete random variable.

Coding males as 1 and females as 0 in a data set illustrates the use of

dummy variables

The difference between the first and third quartile is called the

interquartile range

The limitation of covariance as a descriptive measure of association is that it

is very sensitive to the units of the variables.

In a generic box plot, the x inside the box indicates the location of the

mean

The median can be described as the

middle observation

The median can also be described as:

middle observation when the data values are arranged in ascending order

Changing the location of fields in a pivot table is known as:

pivoting

A measure of variability, what is defined as the maximum value minus the minimum value?

range

As a measure of variability, what is defined as the maximum value minus the minimum value?

range

The modeling process discussed in Data Analysis & Decision Making book is a

seven-sep process

A histogram that is positively skewed is also called

skewed to the right

The daily closing values of the Dow Jones Industrial Average are examples of

time-series data

The count of categories is the only meaningful way to summarize categorical data.

true

Which of the following are true? a. Three important themes run through the book. Two of them are in the title: data analysis and decision making. The third is dealing with uncertainty. b.Data analysis includes data description, data inference, and the search for relationships in data. c.Decision making includes optimization techniques for problems with no uncertainty, decision analysis for problems with uncertainty, and structured sensitivity analysis. d.Dealing with uncertainty includes measuring uncertainty and modeling uncertainty explicitly into the analysis .e.All of these options

.e.All of these options

There are four quartiles that divide the values in a data set into four equal parts.

False

Time series graphs chart values of one or more time series, using time on the vertical axis.

False

Using the standard normal distribution, the Z-score representing the 5th percentile is 1.645

False