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