AP Statistics

Chebyshev's Rule

100( 1 - 1/k²)

Which of the following indicates that an association between x and y is positive?

A positive Pearson's correlation coefficient

A good fit of the simple linear regression model would be characterized by

A relatively large r² and a relatively small Se

Which of the following are true statements: I. In all normal distributions, the mean and median are equal II. All bell-shaped curves are normal distributions for some choice of μ and σ III. Virtually all the area under a normal curve is within three standard deviations of the mean, no matter what the particular mean and standard deviation are

I and III

Which of the following is true I. The sampling distribution of p has a mean equal to π II. The sampling distribution of p has a standard deviation equal to √np(1-p) III. The sampling distribution of p is always symmetric

I only

Which of the following are true statements? I. The mean of a discrete random variable x will get closer and closer to a specific value as the number possible values of x increases. II. The standard deviation of a random variable is never negative III. The variance of a random variable is never less than the standard deviation.

II only

what are some properties of a geometric experiment?

Outcomes of different trials are independent, each trial can result in one of two possible outcomes, the probability of success is the same for all trials, the number of trials is necessarily greater than zero

Randomization, as a strategy in experimental design, would be unsuccessful if

aspects of the experimental condition other than the values of the explanatory variable, systematically favors a treatment

Which of the following random variables is not continuous? a) the birth weight of a newborn baby b) the number of fumbles in a football game c) the length of life of a 60 watt light bulb d) time from take-off to landing of an airline flight e) the velocity of an asteroid

b) the number of fumbles in a football game

In a study a dexterity, data was taken on 100 individuals. The variables measured for each person were the number of errors in picking up a dime in 50 trials, and the total time it took to pick up the dime 50 times. The data set is therefore

bivariate

Which of the following is not a property of a binomial experiment? a) it consists of a fixed number of trials, n b) Outcomes to different trials are independent c) Each trial can result in one of several different outcomes. d) Observations consist of the number of successes from each trial of the experiment e) The probability of success is constant for each trial

c) Each trial can result in on e of several different outcomes

The event, not A is called the ________ of event A

complement

The distinction between descriptive and inferential statistics is that

descriptive statistics describe data sets, inferential statistics involve generalizing to populations

An experiment is a planned intervention undertaken to observe

explanatory variables

By definition, strata are groups of population units that

form well defined subpopulations

It is possible for a distribution to be

heavy tailed and skewed, light tailed and skewed, and symmetric and normal

A point is called an influential point if:

it plays a large role in determining the slope of the least squares line

The sampling frame is the

list of all elements in a population

least sensitive < sensitive < most sensitive

median < trimmed mean < mean

A distribution can have more than one

mode

A data set considering of observations on two or more attributes is called a(n)

multivariate data set

The bias that occurs because observations were not made of all individuals selected for a sample is

non-response bias

A treatment that has no active ingredients is a(n)

placebo treatment

Of the following, which is not true of r?

r is always between 0 and 1

The z-score and percentile are measure of

relative location

The design strategy of making multiple observations for each experimental condition is

replication

When regressing y on x, y is referred to as the

response variable

By definition, a subset of a population selected for study is a

sample

The observed value of a statistic will differ from sample to sample. This phenomenon is known as:

sampling variability

The term used to describe the bias that occurs if some segment of a population is systematically excluded from a sample is

selection bias

Blocking would be unsuccessful if

the blocks were heterogeneous on the blocking factor

Which of the following random variable is not discrete?

the distance traveled by a motorcycle on one gallon of gas

The Empirical Rule can be used when assessing a distribution if

the distribution is approximately normal

Suppose that a frequency distribution and a cumulative frequency distribution are constructed from the same data, using the same classes. Then, for each class,

the frequency ≤ the cumulative frequency

Suppose I have a set of data within 5 numbers: -6.0, -4.5, 0, 5.0, and an unknown 5th number. For these 5 data points, which of the following statistics can NEVER be greater than zero?

the median

For which of the following statistics would one not need to put the data in order from smallest to largest?

the variance

Suppose that for set of numeric data, where the numbers are not all different, the standard deviation is less than 1.0. Then is must be true that

the variance < the standard deviation

Two variables are confounded if

their effects on the response variable cannot be distinguished

In utilizing direct control, which of the following are held constant?

values of an extraneous variable

A characteristic whose value may change from one individual to another is a

variable

The slope of the regression line and the correlation between two variables is related in the following way

The slope and correlation must be a different sign

Central limit theorem

When n is sufficiently large, the sampling distribution of x̅ is well approximated by a normal curve

A study cannot be an experiment if

a procedure of random assignment to treatments is not performed

A numerical variable whose value depends on the outcome of a chance experiment is called

a random variable

A normal probability plot suggests that a normal probability model is plausible when:

a substantial linear pattern is present in a plot