101 terms

inferential statistics

To study the impact of advertising on various market segments, market researchers use ___________ .

a discrete random variable

The random variable, "number of people who arrive at a store during a 15-minute interval," is an example of ___________.

collection, analysis, interpretation, and presentation of data

Statistics, as a course of study, deals with __________ .

Nominal

Numbers that are used to classify or categorize the respondents of a survey into different ethnic groups represent which level of data measurement?

a population

The collection of all persons, objects, or items of interest on which data is collected for conducting statistical analysis is called __________.

a sample

A small portion or a subset of the population on which data is collected for conducting statistical analysis is called __________.

discrete random variables

Random variables which are usually generated from experiments in which the observations or things are "counted" rather than "measured", are __________.

continuous random variables

Random variables which are usually generated from experiments in which the observations or things are "measured" rather than "counted", are __________.

census

The activity or the process of collecting the data on the population is called __________.

Ordinal

Numbers that are used to represent the different grades (such as A, B, and C) that students get in a course represent which level of data measurement?

descriptive statistics

When you use the data gathered from a group to describe or reach conclusions about that same group, you are performing __________.

a parameter

A descriptive measure of a population is called __________.

With interval level data, the zero-point is not a natural or fixed point.

Which of the following statements captures a key aspect of interval level data?

a continuous random variable

The average height of students in a sample of ten students randomly selected from your class is __________.

2. grouped into different classes

To render large amounts of data manageable for decision-making, the data are __________.

range

The difference between the largest and the smallest numbers in a data set containing raw data is called __________.

class frequency

A histogram is a vertical bar chart on an X-Y plane, in which the labels along horizontal (or X) axis represent the class end points and the bars along the vertical (or Y) axis show the ____________.

range of the data

The first step in constructing a frequency distribution is to determine the ___________.

subject to the user's discretion

The number of classes in a frequency distribution is ___________.

individual class frequency divided by the total frequency

Relative frequency for an individual class is the ___________.

individual class frequency plus the total frequency of all preceding classes

Cumulative frequency for an individual class is the ____________.

one

Relative frequencies for a set of data must add up to ___________.

changing the scales of the axes

One of the ways by which graphical displays such as a histogram are used to "lie with statistics" is by __________.

most frequently occurring number in the data set

The mode of a set of numerical data is the __________.

Four

Quartiles divide a group of data into how many subgroups?

is equal to zero

The sum of deviations from the mean for a data set __________.

mean

The central tendency or center of a set of data may be described by its ___________.

squaring the standard deviation

If we know the standard deviation, we can find the variance by ___________.

middle value in the ordered set of data

The median of a set of numerical data is the __________.

positive

Mean absolute deviation of a set of numerical data is always ___________.

similar except for (n - 1) in the denominator instead of n

Compared to the formula for determining the population variance, the formula for determining the sample variance is __________.

variability of a data set

Mean absolute deviation, standard deviation, and variance are all measures of the ___________.

the likelihood of the outcome

Probability of an outcome in a decision-making situation with uncertainty is __________ .

.75

Which of the following is an admissible value for the probability of an uncertain outcome?

relative frequency of the occurrence

One of the methods of assigning probabilities to an uncertain outcome based on past data is to use the __________ .

sample space

A listing of all elementary outcomes (i.e. the outcomes which cannot be broken down into other events) of an experiment (i.e. a decision making situation under uncertainty) is called a __________ .

classical method

The method of assigning probabilities based on the laws and rules pertaining to an experiment is called the ___________.

n underscore e / N

In an experiment in which the total possible number of outcomes is N and ne is the number of outcomes in which the event of our interest occurs, then according to the classical method the probability of the event is ___________.

subjective probability

Belinda Bose is reviewing a newly proposed advertising campaign. Based on her 15 years experience, she believes the campaign has a 75% chance of significantly increasing brand name recognition of the product. This is an example of assigning probabilities using the ____________ method.

4/3

Which of the following is NOT a legitimate probability value?

the sample space

The list of all elementary events for an experiment is called __________.

mutually exclusive events

In any statistical experiment if the occurrence of one event precludes the occurrence of the other events, the events of the experiment are called __________ .

15

Two operations must be done to finish a job. If the first operation may be done in three different ways and the second operation in five different ways, how many different ways are there to do the job?

is equal to zero

If two events, A and B, are mutually exclusive, the probability of A given the information that the event B has occurred __________ .

36

How many elementary events are in the sample space of the experiment of rolling a pair of 6-faced dice?

P (A ∩ B) = 0

If two events, Event A with probability P(A) and Event B with probability P(B) are mutually exclusive, then ____________.

P(B) = 1 - P(A)

If two events, Event A with probability P(A) and Event B with probability P(B) are complementary events then __________.

216

How many elementary events are in the sample space of the experiment of rolling a 6-faced die thrice?

560

How many different combinations of a 3-member debating team can be formed from a group of 16 qualified students?

P(A U B) = P(A) + P(B)

If two events, Event A with probability P(A) and Event B with probability P(B) are mutually exclusive, then ___________.

conditional probability

The probability of one event given the information that another related event has occurred is an example of __________ .

P(A ∩ B) = P(A) x P(B)

If two events, Event A with probability P(A) and Event B with probability P(B) are independent, then ___________.

P(A)

If two events, Event A with probability P(A) a Event B with probability P(B) are independent, then the conditional probability P(A|B) is ___________.

P(A|B) = P(A ∩ B) / P(B)

Given two events, Event A with probability P(A) and Event B with probability P(B), P(A|B) the conditional probability of A given B is given by ___________.

discrete random variables

Random variables which are usually generated from experiments in which the observations or things are "counted" rather than "measured", are __________.

Two mutually exclusive outcomes

Tossing a coin is a popular example of a binomial experiment. Which of the following describes the possible outcomes of any single trial of a binomial distribution experiment?

60

60% of all graduate students in the music department at a large university are women. If a sample of 100 music graduate students is selected at random, how many women do you expect to see in that sample?

change from trial to trial

Suppose we have to randomly select 5 applicants from a pool of 24 applicants, 16 of whom are men and 8 are women. Consider this selection as five trials of a random experiment. In this experiment, the probability of selecting a woman will __________.

a discrete random variable

The random variable, "number of people who arrive at a store during a 15-minute interval," is an example of ___________.

a continuous random variable

The random variable which describes the "time between customer arrivals at a retail store," is an example of ____________.

binomial distribution

The number of defectives in samples of 30 units taken periodically from the output of a machine that has a 5% defective rate is a random variable which follows a ____________.

1.5

The expected number of defectives in samples of 30 units taken periodically from the output of a machine that has a 5% defective rate is ___________.

30

In the distribution of a random variable x, which is binomial with number of trials n = 30 and the probability of success p = 0.80, the largest value of x that can occur is ___________.

one

The graph of a probability distribution of a continuous random variable is a curve (Note: a straight line is a special type of curve) between two points which represent the minimum and the maximum possible values the random variable can take. The area under the whole curve is equal to __________.

the area under the distribution curve between the two points

For continuous distributions, probabilities of outcomes occurring between two points are determined by __________.

normal

Most often, random variables describing measured human characteristics such as height, weight, IQ, and scholastic achievement along with many characteristics of other living things such as trees and animals are generally thought to be associated with which probability distribution?

1 / (b - a)

If a continuous random variable is uniformly distributed between a and b, with b > a, the height of the rectangle that describes the graph of its distribution is equal to ___________.

(b - a) / √12

If a continuous random variable is uniformly distributed between a and b, and b > a, the standard deviation of the distribution is equal to ___________.

discrete

Which one of the following is not a characteristic of a normal distribution?

standard deviation

A normal distribution is defined by two parameters, the mean and the ____________.

standard normal or the z- distribution

All normal distributions can be converted into a single distribution called the ____________.

0 and 1

The mean and the standard deviation of the z distribution are __________ and ___________.

The x value is below the mean of the distribution

If the z-value of a given x value is negative, it means that ___________.

accessing the population may be impossible

One of the reasons for taking a sample instead of conducting a census is this: ___________.

the same probability of being included in the sample

In random sampling every unit of the population has ____________.

stratified random sampling

A type of random sampling in which the population is divided into non-overlapping subpopulations is called ___________.

systematic sampling

A type of random sampling in which every kth item (where k is some number) in the population is selected for inclusion in the sample is called ____________.

pure chance

Sampling error is caused by ___________.

normally distributed

If reasonably large sized samples (i.e., samples of 30 elements or more) are drawn from a uniform distribution, the sample means will be approximately ____________.

μ

If samples of size n are drawn from a population with mean μ standard deviation σ, the mean of the distribution of the sample means is ___________.

σ / √ n

If samples of size n are drawn from a population with mean μ standard deviation σ, the standard deviation of the distribution of the sample means is ____________.

standard error of the mean

The standard deviation of the sample means is called ____________.

become smaller

As the sample size n increases, the standard error of the means will ____________.

normally distributed

By applying the central limit theorem, the distribution of sample proportions can be approximated by a sampling distribution that is ____________.

p

If samples of size n are drawn from a population with a population proportion p, the mean of the distribution of the sample proportions is ____________.

√(p q) / n

If samples of size n are drawn from a population with a population proportion p, and we denote q = (1-p), the standard error of sample proportions is given by ____________.

a point estimate

When a company with thousands of employees reports a sample statistic (a single number) as the estimate of the population mean number of days of work missed per employee due to illness during a year, it is providing __________.

a interval estimate

When a company with thousands of employees reports a range of values based on the sample statistic as the estimate of the population mean number of days of work missed per employee due to illness during a year, it is providing __________.

+ /- 1.96

In a normal distribution, what values of z should we choose if we want 95% of the area under the curve symmetrically distributed around the mean?

the sample mean

The point estimate of the population mean is ___________.

.025

In the estimation of the population mean when the population σ is known, to construct a confidence interval for a level of confidence equal to 95%, we use z values that leave out, in the lower and the upper tails of the normal distribution, an area equal to ___________.

normal distribution

If samples of small size, n, (say n = 10) are drawn from a normally distributed population, the distribution of the sample means is distributed approximately as a ___________.

t- distribution

In the estimation of the population mean when the population σ is unknown, to construct a confidence interval estimate, we use the ____________.

t 0.05, 17

In order to construct a 90% confidence interval for the population mean when the population standard deviation σ is unknown and the sample of size n = 18, the appropriate t-value to use is represented by ____________.

t 0.005, 19

In order to construct a 99% confidence interval for the population mean when the population standard deviation σ is unknown and the sample of size n = 20, the appropriate t-value to use is represented by ____________.

population porportion

To get an idea of its market share, a company would estimate the __________.

the sample size

In the inferential statistics process pertaining to the estimation of a population parameter, the sampling error is closely tied to __________.

the sample porportion

The point estimate of the population proportion is ____________.

n · p > 5 and n · (1-p) > 5

When developing the interval estimates for the population proportion p using the sample proportion based on samples of size n, a z-distribution can be used if ___________.

decreases as the population standard deviation decreases

In the estimation of population parameters like population mean and population proportion, for given values of the desired error of estimation and the desired confidence level, the sample size n ____________.

Companies with more than $1 billion in assets spend more than 10% of their annual budget on advertising.

Which of the following is an example of a research hypothesis, i.e. a statement of what the researcher believes will be the outcome of an experiment or study?