BAN203 quiz quest

Which of the following best describes the concept of probability?

It is a measure of the likelihood that a particular event will occur.

Sampling done without replacement means that

b.each member of the population can be sampled only once

Which of the following are considered numerical summary measures?

correlation and covariance

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

data mining

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

dummy variables

We can infer that there is a strong relationship between two numerical variables when

either of these options

Which of the following distributions is appropriate to measure the length of time between arrivals at a grocery checkout counter?

exponential

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

false

If P(A and B) = 0, then A and B must be collectively exhaustive.

false

Mean absolute deviation (MAD) is the average of the squared deviations.

false

Suppose A and B are two events where P(A) = 0.5, P(B) = 0.4, and P(A and B) = 0.2, then P(B/A) = 0.5.

false

The Filters field of a pivot table contains the data you want summarize

false

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

false

The relative frequency of an event is the number of times the event occurs out of the total number of times the random experiment is run.

false

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

false

Unlike histograms, box plots depict only one aspect of a variable.

false

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

false

f the standard deviation of X is 15, the covariance of X and Y is 94.5, the coefficient of correlation r = 0.90, then the variance of Y is 7.0.

false

if events A and B have nonzero probabilities, then they can be both independent and mutually exclusive.

false

What is the most common type of chart for showing the distribution of a numerical variable?

histogram

The difference between the first and third quartile is called the

interquartile range

If the random variable X is exponentially distributed with parameter = 1.5, then P(2X 4), up to 4 decimal places, is

not .25, not .6667

The standard normal distribution has a mean and a standard deviation respectively equal to

o and 1

The tool that provides useful information about a data set by breaking it down into categories is the

pivot table

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

range

1- prob of A is the:

rule of complements

A histogram that is positively skewed is also called

skewed to right

A line or curve superimposed on a scatterplot to quantify an apparent relationship is known as a(n)

trend line

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

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

Cross-sectional data are data on a population at a distinct point in time, whereas time series data are data collected over time.

true

Problems in data analysis where we want to compare a numerical variable across two or more subpopulations are called comparison problems.

true

Strongly related variables have a relationship close to zero if the relationship is nonlinear.

true

The Poisson random variable is a discrete random variable with infinitely many possible values.

true

The binomial distribution deals with consecutive trials, each of which has two possible outcomes.

true

The binomial distribution is a discrete distribution that deals with a sequence of identical trials, each of which has only two possible outcomes

true

The correlation between two variables is a unitless and is always between -1 and +1.

true

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

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 value of the mean times the number of observations equals the sum of all of the data values.

true

The variance of a binomial distribution is given by the formula , where n is the number of trials, and p is the probability of success in any trial.

true

Two events are said to be independent when knowledge of one event is of no value when assessing the probability of the other.

true

Two or more events are said to be mutually exclusive if at most one of them can occur.

true

The Poisson and Exponential distributions are commonly used in which of the following applications

.

If A and B are mutually exclusive events with P(A) = 0.30 and P(B) = 0.40, then the probability that either A or B occur is:

.7

If X is a normal random variable with a standard deviation of 10, then 3X has a standard deviation equal to

30

If a value represents the 95th percentile, this means that

95% are below you

The multiplication rule for two events A and B is: P(A and B) = P(A|B)P(A).

False