Stats Midterm I Review

The complement of "at least one" is ___.

"none."

"At least one" is equivalent to ____.

"one or more"

Which of the following is NOT a principle of probability? a. All events are equally likely in any probability procedure. b. The probability of any event is between 0 and 1 inclusive. c. The probability of an impossible event is 0. d. The probability of an event that is certain to occur is 1.

All events are equally likely in any probability procedure.

Which word is associated with multiplication when computing probabilities?

And

Which of the following is NOT a procedure for determining whether it is reasonable to assume that sample data are from a normally distributed population? a. Visual inspection of a Histogram to determine if its roughly "bell shaped" b. Constructing a probability plot (QQ) c. Identifying the outliers. d. Checking that the probability of an event is 0.05 or less.

Checking that the probability of an event is 0.05 or less.

Which of the following is always true? a. For skewed data, the mode is farther out in the longer tail than the median. b. Data skewed to the right have a longer left tail than right tail. c. The mean and median should be used to identify the shape of the distribution. d. In a symmetric and bell-shaped distribution, the mean, median, and mode are the same.

In a symmetric and bell-shaped distribution, the mean, median, and mode are the same.

____ are sample values that lie very far away from the majority of the other sample values.

Outliers

P(A) + P(mean of A) = 1 is one way to express the ____.

Rule of complementary events.

Which of the following is NOT a characteristic of the mean?

The mean is called the average by statisticians.

What does P(B|A) represent?

The probability of event B occurring after it is assumed that event A has already occurred.

Which of the following is not a requirement of the binomial probability distribution? a. Each trial must have all outcomes classified into two categories b. The trials must be dependent. c. The procedure has a fixed number of trails. d. The probability of a success remains the same in all trails.

The trails must be dependent (For a binomial distribution, the trials must be independent.)

Which of the following is NOT true about statistical graph. a. Similar graphs can be constructed in order to compare data sets. b. They utilize areas or volumes for data that are one-dimensional in nature. c. They can be used to consider the overall shape of the distribution. d. They can be used to identify extreme data values.

They utilize areas or volumes for data that are one-dimensional in nature. (Utilizing 2-or 3- dimensional pictures to represent 1- dimensional data is poor practice and distorts the data.

Which characteristic of data is a measure of the amount that the data values vary?

Variation

Which of the following is NOT a property of the standard deviation? a. When comparing variation in samples with very different means, it is good practice to compare the two standard deviation. b. The value of the standard deviation is never negative c. The st. dev. is a measure of variation of all data values from the mean. d. The units of the st. dev. are the same as the units of the original data.

When comparing variation in samples with very different means, it is good practice to compare the two sample standard deviations.

In a probability histogram, there is a correspondence between ___.

area and probability.

Which of the following is NOT a measure of center?

census

____ is the difference btw two consecutive lower class limits or two consecutive lower class boundaries in a frequency distribution.

class width

A ___ probability of an event is a probability obtained with knowledge that some other event has already occurred.

conditional (knowledge)

A ___ random variable has infinitely many values associated with measurements.

continuous

Methods used that summarize or describe characteristics of data are called ___ statistics.

descriptive

A ___ random variable has either a finite or a countable number of values.

discrete

Events that are ____ cannot occur at the same time.

disjoint (Disjoint events are mutually exclusive and cannot occur at the same time.)

The ___ of a discrete random variable represents the mean value of the outcomes.

expected value

The heights of the bars of a histogram correspond to ___ values.

frequency

A ____ indicates the shape and nature of the distribution of a data set.

frequency distribution

Two events A and B are ___ if the occurrence of one does not affect the probability of the occurrence of the other.

independent

A value at the center or middle of a data set is a(n)

measure of center

The measure of center that is the value that occurs with the greatest frequency is the ____.

mode

A(n) ____ distribution has a "bell" shape.

normal

A data value is considered ___ if its z-score is greater than or equal to -2, or less than or equal to 2.

ordinary

A ___ variable is a variable that has a single numerical value, determined by chance, for each outcome of a procedure.

random

What measure of variation is very sensitive to extreme values?

range

A ___ histogram has the same shape and horizontal scale as a histogram, but the vertical scale is marked with relative frequencies instead of actual frequencies.

relative frequency

In a ___ distribution, the frequency of a class is replaced with a proportion or percent.

relative frequency

The Range Rule of Thumb roughly estimates the st. dev. of a data set as ___.

s = range/4

The ___ for a procedure consists of all possible simple events or all outcomes that cannot be broken down further.

sample space

A ___ is a plot of paired data (x,y) and is helpful in determining whether there is a relationship between the two variables.

scatterplot

A histogram aids in analyzing the ___ of the data.

shape of the distribution

Class width is found by ___.

subtracting a lower class limit from the next consecutive lower class limit

In the binomial probability formula, the variable x represents the ___.

the number of successes

P (A or B) indicates ____.

the probability that in a single trial, event A occurs, event B occurs, or they both occur.

The bars in a histogram ___.

touch (without gaps)

A data value is considered ___ if its z-score is less than -2 or greater than 2.

unusual

The square of the st. dev. is called the ___.

variance.

When a data value is converted to a standardized scale representing the number of st. dev. the data value lies from the mean, we call the new value a __.

z-score.