Statistics Final Multiple Choice

In constructing a frequency distribution, the approximate class width is computed as

(largest data value - smallest data value)/number of classes

The coefficient of correlation ranges between

-1 and +1

In a standard normal distribution, the probability that Z is greater than 0 is

0.5

If a penny is tossed three times and comes up heads all three times, the probability of heads on the 4th trial is

1/2

The exponential probability distribution is used with

A continuous random variable

The uniform probability distribution is used with

A continuous random variable

The weight of an object is an example of

A continuous random variable

The binomial probability distribution is used with

A discrete random variable

A histogram is

A graphical presentation of a numerical variable's distribution

A portion of the population selected to represent the population is called

A sample

A continuous random variable may assume

All values in an interval or collection of intervals

Any process that generates well-defined outcomes is

An experiment

A probability distribution showing the probability of x successes in n trials, where the probability of success does not change from trial to trial is termed a

Binomial Probability Distribution

If you are conducting an experiment where the probability of a success is .02 and you are interested in the probability of 4 successes in 15 trials the correct probability function to use is the

Binomial Probability Function

Two events with nonzero probabilities

Can not be both mutually exclusive and independent

In an experiment, events A and B are mutually exclusive. If P(A)=0.6 then the probability of B

Cannot be larger than 0.4

When the assumption of equally likely outcomes is used to assign probability values, the method used to assign probabilities is referred to as the

Classical Method

If a manager needs how precise is production of two different products, bottled water and cookie dough, the best way to do so is by looking at the

Coefficient of Variation

The counting rule that is used for counting the number of experimental outcomes when n objects are selected from a set of N objects where order of selection is not important is called

Combination

A numerical measure of linear association between the two variables is the

Covariance

The summaries of data, which may be tabular, graphical or numerical are referred to as

Descriptive Statistics

Refer to Exhibit A. The appropriate probability distribution for the random variable is

Discrete

A random variable that can assume only a finite number of values is referred to as a

Discrete Random Variable

Quantitative data refers to data obtained with a

Either interval or ratio scale

Which of the following is a characteristic of an experiment where the binomial probability distribution is applicable?

Exactly two outcomes are possible on each trial

The center of a normal curve is

Is the mean of the distribution

The numerical value of the standard deviation can never be

Negative

In a scatter diagram, a trend line that is upward sloping suggests that the relationships between two categorical variables with nominal scale is Nonexistent Positive Negative

None of the above are correct

The mean of the sample Is always smaller than the mean of the population from which the sample was taken Can never be 0 Can never be negative

None of these alternatives is correct

The union of two events with nonzero probabilities cannot be less than one cannot be one could be larger than one

None of these alternatives is correct.

In a questionnaire, respondents are asked to mark their highest degree of education achieved. This is an example of the

Ordinal Scale

When dealing with the number of occurrences of an event over a specified interval of time or space, the appropriate probability distribution is a

Poisson Distribution

When dealing with the number of occurrences of an event over a specified interval of time or space, the appropriate probability distribution is a

Poisson distribution

When a histogram has a longer tail to right it is said to be

Positively Skewed

A numerical description of the outcome of an experiment is called a

Random Variable

The reversal of conclusions based on aggregate and unaggregated data is called

Simpson's paradox

In a sample of 400 students in a university, 80 or 20%, are Business majors. Based on the above information, the school's paper reported that "20% of all the students at the university are Business majors" This report is an example of

Statistical Inference

Which of the following is not a measure of dispersion

The 50th percentile (median)

A weighted average of the value of a random variable, where the probability function provides weights is known as

The expected value

The multiplication law is potentially helpful when we are interested in computing the probability of

The intersection of two events

In a binomial experiment

The probability does not change from trial to trial

A cumulative relative frequency distribution shows

The proportion of data items with values less than or equal to the upper limit of each class

Exhibit A

The random variable x is the number of occurrences of an event over an interval of 10 minutes. It can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. It is known that the mean number of occurrences in 10 minutes is 5.3.

The measure of dispersion that is influenced most by extreme values is

The range

The addition law is potentially helpful when we are interested in computing the probability of

The union of two events

Larger values of the standard deviation result in a normal curve that is

Wider and flatter

If two events are mutually exclusive, then their intersection

Will be equal to zero

A normal probability distribution

can have any value of the mean

The standard deviation of a normal distribution

cannot be negative

A method of assigning probabilities which assumes that the experimental outcomes are equally likely is referred to as the

classical method

The expected value of a discrete random variable

is the average value for the random variable over many repeats of the experiment

The probability of the occurrence of event A in an experiment is 1/3. If the experiment is performed 2 times and event A did not occur, then on the 3rd trial event A

may occur

In a standard normal distribution, the

mean is 0 and the standard deviation is 1

The 50th percentile is the

median

The intersection of two mutually exclusive events

must always be equal to 0

The function that defines the probability distribution of a continuous random variable is a

probability density function

A method of assigning probabilities based on historical data is called the

relative frequency method

For a continuous random variable x, the probability density function f(x) represents

the height of the function at x

For a uniform probability density

the height of the function is the same for each value of x

The negative value of Z indicates that

the number of standard deviations of an observation is to the left of the mean

Which of the following is not a property of a binomial experiment

the probabilities of the two outcomes can change from one trial to the next