Chap 6 Standard Errors

Question 1

Central Limit Theorem

Answer 1

The fact that as a sample size increases, the sample distribution of the mean becomes increasingly normal, regardless of the shape of the distribution of the sample.

Question 2

Degrees of Freedom

Answer 2

Roughly the minimum amount of data needed to calculate a statistic. More practically, it is a number or numbers, used to approximate the number of observations in the data set for the purpose of determining statistical significance.

Question 3

Expected Value of the Mean

Answer 3

The value of the mean one would expect to get from a random sample selected from a population with a known mean.
i.e. if one knows the population has a mean of 5 on some variable, one would expect a random sample selected from the population will also have a mean of 5.

Question 4

Inferential Statistics

Answer 4

Statistics generated from sample data that are used to make inferences about the characteristics of the population the sample is alleged to represent.

Question 5

Sampling Distribution of the Differences b/w the Means

Answer 5

The distribution of scores that would be generated if one were repeatedly draw two random samples of a given size from a 2 populations and calculate the difference b/w the sample means

Question 6

Sampling Distribution of the Mean

Answer 6

The distribution of scores that would be generated if one were to repeatedly draw random samples of a given size from two population and calculate the mean for each sample drawn.

Question 7

Sampling Distribution

Answer 7

A theoretical distribution of any statistic that one would get by repeatedly drawing random samples of a given size from the population & calculating the statistic of interest for each sample.

Question 8

Standard Error

Answer 8

The standard deviation of a sampling distribution.

Question 9

Statistically Significant

Answer 9

A term indicating that a phenomenon observed in a sample( or samples) has meaningful implications for the population.
i.e. That the difference b/w a sample mean and a population mean is statistically significant or that a relationship observed b/w 2 variables in a sample is strong enough, relative to the standard error, to indicate a relationship b/w the 2 variables in the population from which the sample was selected.

Question 10

sx ̅

Answer 10

The standard error of the mean estimated from the sample standard deviation.
i.e. when a population standard deviation is unknown

Question 11

ox ̅

Answer 11

The standard error of the mean when the population standard deviation is known.