cj 202 final

The level of confidence is defined as estimate interval?

The probability that a confidence interval contains the population parameter

Confidence levels are set?

a priori-prior to the construction of the confidence interval

The uncertainty introduced into a statistic by the fact that any sample that is drawn is one of infinite samples that could have been drawn, and that a sample statistic is therefore not necessarily equal to the population parameters is the definition of which of the following?

Sampling error

What acts as a sort of "bubble" that introduces flexibility into the estimate of the population parameter?

A confidence interval

: A researcher has decided upon an alpha level of .05. Based on this, what is the chance that the confidence level the researcher calculates will not include the true population parameter?

.5%

Which distribution is used to construct confidence intervals for means when N ≤ 99?

T-Distrubution

In the t distribution, df is related to?

Sample Size

A 99% confidence level would produce a confidence interval that has a greater chance than a 95% one of being correct, but would be wider and less precise.

True

Confidence intervals for proportion make use of the t distribution, regardless of sample size.

False

The Central Limit Theorem states distribution mean bridge between the theoretical distributions and the empirical observations population under study, thus ensuring a Normally distributed sample sampling distribution will be normally distributed.

that any time descriptive statistics are computed from an infinite number of large samples the resulting

The mean of the sampling distribution is equal to>

The true population mean

What is the area under the t distribution curve?

1.00

Which of the following is an important distinction between the z and t distributions? available for use by research scientists

. The t distribution changes shape depending on sample size; the z distribution does not

What is one characteristic of a parameter that makes it differ from a statistic? only in basic descriptions of a sample

A parameter is fixed, while it is possible for a statistic to vary from sample to sample

Population parameters vary from sample to sample because of sampling error.

False

In the t distribution as sample size increases the curve becomes more and more normal until it looks identical to the Z curve.

True

The major difference between proportions and probabilities is?

Proportions are descriptive while probabilities represent predictions

What is the essential difference between the normal curve and the standard normal curve? constructed of raw scores raw scores

The standard normal curve is comprised of Z-scores and the normal curve is constructed of raw scores

The standard normal curve has an area of?

1.00

The area under the curve in the standard normal curve represents?

Proportions & probability

The standard normal curve has a mean of 1 and a standard deviation of 0.

False

In the following list, the only measure of dispersion that is suitable for nominal and ordinal data is:

The variation ratio

The variance is one measure of dispersion that is suitable for use with which of the following levels of measurement?

Ratio

One characteristic of the Standard Deviation is that it can never be?

A negative number

Descriptive statistics that offer information about where the scores in a particular data set tend to cluster are referred to in scientific jargon as what?

Measures of Central Tendency

Which of the following is true about the process of locating the median?

The median position tells a researcher precisely where within the data set the median can be found

Which of the following measures of central tendency can be employed with any level of measurement?

Mode

The maximum value a proportion can take on is 100.00

False

A frequency, proportion, or percent that is obtained through the process of adding a given number to all numbers below it is called what in scientific research?

Cumulative

Categorical variables are generally divided into two distinct types. These are?

Nominal & Ordinal

The level of confidence is defined as?

The probability that a confidence interval contains the population parameter

A researcher has decided upon an alpha level of .05. Based on this, what is the chance that the confidence level the researcher calculates will not include the true population parameter?

.5%

A 99% confidence level would produce a confidence interval that has a greater chance than a 95% one of being correct, but would be wider and less precise.

True

The mean of the sampling distribution is equal to?

The true population mean

The standard normal curve has a mean of 1 and a standard deviation of 0.

False

Which of the following measures of central tendency can be employed with any level of measurement?

Mode

While Z-scores can be used to find areas under the standard normal curve, areas cannot be used to reverse the process and find corresponding Z-scores.

False

Population parameters vary from sample to sample because of sampling error.

False

What is a critical value?

The value of Z or t associated with a given alpha level

A 99% confidence level would produce a confidence interval that has a greater chance than a 95% one of being correct, but would be wider and less precise.

True

The ultimate "goal" in conducting a statistical test is?

To decide whether to retain the null hypothesis or to reject the null hypothesis

Which of the following is true with respect to researchers and the possibility of errors?

Researchers can minimize the probability that they are wrong about a decision but they can never eliminate it

The ultimate goal for the quantitative researcher is to be able to generalize from a population to a sample.

False

Which of the following test designs is used when researchers need an experimental group and a control group but are unable to use random assignment to create the groups?

Matched Pairs

Which of the following designs entails measuring a characteristic in a sample, applying a treatment to the sample, and then measuring that characteristic again?

Repeated measures designs

Which of the following would be considered a hypothesis test in which the entire alpha is placed in either the upper/positive or lower/negative tail such that there is only one critical value of the test statistic?

One tailed-test

Two-population tests for differences between proportions

Use only the Z-distrubtion

A professor predicts that states with large sea ports, such as Louisiana or Virginia, have more homicides than states without large port cities, such as Arkansas or Kentucky. Which test would be most appropriate for this purpose?

A one-tailed test

Matched pairs and repeated measures are both types of dependent samples designs.

True

A t-test with the alternative hypothesis H1: µ1 ≠µ2 would be a one-tailed test.

False

A t-test is intended to be used with a categorical DV.

False

When true differences between groups substantially outweigh the random fluctuations present within each group, the ANOVA statistic

Will be small

Which of the following is the correct Ho for the ANOVA?

Ho: μ1 = μ2 = μ3

Post hoc tests are?

Conducted when the null is rejected in ANOVA in order to determine the number and location of differences between groups

ANOVA relies upon a theoretical distribution whose curve shape?

is determined by the degrees of freedom and the alpha level

What are the limits to the number of classes that can be successfully analyzed using ANOVA?

there is no limit to the number of classes that can be analyzed by an ANOVA

In ANOVA, there are three types of variances analyzed.

False

Which of the following would be considered an alternative to a histogram for use with continuous data?

Frequency Polygon

The median is the simplest measure of central tendency.

False

If a z score is negative, then the area associated with that score will also be negative

False

One characteristic of the Standard Deviation is that it can never be?

A negative number

The level of measurement that is numeric, rank-orderable, and has equal intervals between adjacent points but that does not have a true zero is?

Nominal

The error of assuming that a statistical relationship present in a group applies uniformly to all individuals or objects within that group is known as what?

Ecological Fallacy

Continuous variables can be made into categorical variables.

True

A standardized form of a frequency that ranges from 0.00 to 1.00 is referred to as?

Proportion

Which of the following would be considered an alternative to a histogram for use with continuous data?

Frequency polygon

A frequency, proportion, or percent that is obtained through the process of adding a given number to all numbers below it is called what in scientific research?

Cumulative

The property of the mean that causes all deviation scores based on the mean to sum to zero is referred to by social scientists as what?

Midpoint of the magnitude

The distance between the mean of a data set and any given raw score in that set is known as?

Deviation Score

The primary criterion on which to base a decision regarding which measure of central tendency to use is a given variable's level of measurement?

True

Raw data points that are exactly equal to the mean will have deviation scores of 1.00.

False

The sum of the deviation scores used in the calculation of the variance and standard deviation will always be?

0

While Z-scores can be used to find areas under the standard normal curve, areas cannot be used to reverse the process and find corresponding Z-scores.

False

The logical premises that form a set of predictions about the likelihood of certain events or the empirical results that one would expect to see in an infinite set of trials is the definition of which of the following?

Probability Theory

What is the technique utilized by scientists to standardize the normal curve?

Converting a distribution's raw scores to Z-scores

There is no exact, predetermined shape to the normal curve as every distribution will have its own unique shape.

True

The mean of the sampling distribution is equal to?

The true population mean

Which of the following is true about the t distribution?

It is unimodal

Which of the following is the reason that sampling distributions are theoretical constructs as opposed to empirical distributions?

Sampling distributions are based on the notion of drawing infinite samples from a single population, something that is impossible in reality.

The level of confidence is defined as?

The probability that a confidence interval contains the population parameter

A sample statistic, such as a mean or proportion, that is used to estimate a population parameter is referred to as what?

A point estimate

A researcher has decided upon an alpha level of α = .01. Based on this, what is the chance that the confidence level the researcher calculates will include the true population parameter?

.99%

The hypothesis predicting that there is a relationship between the independent and dependent variables is known as what in scientific research?

the alternative hypothesis

What assumption does a researcher make from the outset of a hypothesis-testing procedure?

The researcher assumes that the Ho is correct

If the Ho is true and a researcher retains it, which of the following scenarios has occurred?

The researcher has committed no error

The obtained value calculated during the analytical portion of an analysis must exceed the critical value in order for the null to be rejected.

True

When two population variances are similar to one another which type of t-test would be most appropriate?

Pooled variance t-test

Which of the following are hypotheses used in two-population tests for differences between proportions?

H0: P1 = P2 and H1: P1 < P2

A researcher is studying robbery rates across cities of different size. He gathers robbery data on a random sample of large, metropolitan cities and on a random sample of smaller urban areas. Which test would he use to find out whether there is a relationship between city size and robbery rates?

Independent Sample T-test

In repeated measures designs?

The samples tested are two samples consisting of the same people of objects measured twice

What is the first step in deciding what type of t-test to use?

Determining if the samples are independent or dependent

When between-group variance is small relative to within-group variance, the ANOVA statistic will?

Be Small

Bivariate relationships represented by correlations are..

Linear

The range of the correlation test statistic is?

-1 to +1

A perfect correlation is indicated by which of the following?

±1

Which theoretical distribution is utilized in correlation?

t-distrubtion

Which of the following alternative hypotheses represents a two-tailed or non-directional test in correlations?

H1: ρ ≠ 0

The coefficient of determination is defined as…

the percent of the variance in the DV that is attributable to the IV

University administrators have recently realized that students who tend spend more in the library achieve higher grades on their final examinations. What type of relationship would a researcher call this tendency?

Positive Relationship

A correlation greater than 1 indicates a perfect relationship.

False