Business Statistics Final Exam Study Guide

Flashcards covering key concepts and definitions from the Business Statistics lecture notes.

What is the margin of error in statistics?

The value added to and subtracted from a point estimate to develop an interval estimate of the population parameter.

How is the t distribution used for estimating means?

It is not restricted to small sample situations when computing an interval estimate for the difference between the means of two populations.

What is the mean in a standard normal distribution?

The mean is zero.

What is the standard deviation in a standard normal distribution?

The standard deviation is one.

What are parameters in a statistical context?

Numerical characteristics of a population.

What is a hypothesis in statistics?

An assumption made about the value of a population parameter.

What does the ANOVA procedure determine?

Whether or not the means of three or more populations are equal.

In the ANOVA procedure, what is a factor?

The independent variable of interest.

What do treatments refer to in ANOVA?

Different levels of a factor.

It is possible to test for equality of three or more population proportions if:

there are three or more populations.

A chi-square distribution is the sampling distribution used for?

Making inferences about a single population’s variance.

What is a multinomial population?

A population where each of its own elements is assigned to only one category.

What is the chi-square distribution used for in goodness of fit tests?

It is the sample distribution for that test.

Describe the standard normal distribution.

It has a mean of 0 and a standard deviation of 1.

What happens to confidence intervals with higher confidence levels?

They become wider.

What does a negative z-value indicate?

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

What are examples of continuous probability distributions?

Uniform, normal, and exponential distributions.

What is convenience sampling?

An example of nonprobabilistic sampling.

The closer the sample mean is to the population mean…

The smaller the sampling error.

What is a sampling distribution?

A probability distribution of all possible values of a sample statistic.

What is the null hypothesis in hypothesis testing?

The tentative assumption about the population parameter.

What does the power curve indicate?

The probability of correctly rejecting the null hypothesis.

What happens to the p-value as the test statistic becomes larger?

The p-value gets smaller.

What is the goodness of fit test?

A statistical test to determine whether to reject or not reject a hypothesized probability distribution for a population.

What is the Marascuilo procedure used for?

Testing for a significant difference between pairs of population proportions.

What does replication refer to in factorial designs?

The number of times each experimental condition is observed.

What is the mean square in ANOVA?

The sum of squares divided by its corresponding degrees of freedom.

What condition is required for using an ANOVA procedure?

The sampled populations must have equal variances.

Normal probability distribution can have the mean of?

Any numerical value.

In developing an interval estimate, if the population standard deviation in unknown, what must be used?

The sample standard deviation.

What is the confidence level?

The ability of an interval estimate to contain the value of the population parameter.

What is the center of a normal curve?

The mean of the distribution.

The probability that a continuous random variable takes any specific value is equal to?

Zero.

As the sample size increases, what decreases?

The standard error of the mean.

What does not lead to probability samples?

Non-random sampling methods, such as convenience or judgmental sampling.

What leads to probability samples?

Random sampling methods, such as cluster sampling and systematic sampling.

What are important applications of the chi-square distribution?

Making inferences about a single population variance, testing for goodness of fit, and testing for the independence of two categorical variables.

What is known as interactions in factorial designs?

The response produced when the treatments of one factor interact with the treatments of another in influencing the response variable.

What are the major characteristics of a standard normal probability distribution?

The mean, median, and mode are all equal, and the distribution is symmetric about the mean.

What are parameters?

numerical characteristics of a population.

What is the sampling error?

The difference between the value of the sample mean and the value of the population mean.

What is the subset of a population selected to represent the population called?

A sample.

It is impossible to construct a frame for what type of population?

An infinite population.

When each data value in one sample is matched with a corresponding data value in another sample, these samples are know as what?

Matched samples.

What is the sampling design that uses a pooled sample variance in cases of equal population standard deviations based on?

Independent samples.

Generally, the _____ sample procedure for inferences about two population means provides better precision than the ____ sample approach.

Matched; Independent

As the sample size becomes larger, the interval estimate…

Becomes narrower.

What is the interval estimate known as?

An estimate of a population parameter that provides an interval of values believed to contain the value of the parameter.

The general form of an interval estimate of a population mean or a population proportion is the _____ plus and minus the _____.

point estimate; margin of error

The degrees of freedom associated with a t distribution are a function of the…

Sample size.

As the degrees of freedom increase, the t distribution approaches the _____ distribution.

normal

As a general guideline, what should the research hypothesis be stated as?

An alternative hypothesis.

In the hypothesis testing procedure, what is a?

The level of significance.

What is the p-value?

A probability.

A simple random sample from an infinite population is a sample selected such that..

Each element is selected independently and from the same population.