7- The Distribution of Sample Means

Question 1

the difficulty of working with samples…..

Answer 1

it provides an incomplete picture of the population

Question 2

sampling distributions

Answer 2

a distributions of statistics obtained by selecting all the possible samples of a specific size from a population

Question 3

rules of sampling distributions

Answer 3

• the sample means should pile up around the population mean
• pile of sample means should form a normal-shaped distribution
• the larger the sample size, the closer the sample mean should be to the population

Question 4

distribution of sample means is almost perfectly normal if…

Answer 4

1- the population from which the samples are selected is a normal distribution
2- the number of scores in each sample is relatively large (30+)

Question 5

standard error of the mean

Answer 5

provides a measure of how much distance is expected on average between a sample mean (M) and the population (μ )

Question 6

bigger sample size = ______ error

Answer 6

bigger sample size = smaller error

Question 7

standard error formula:

Answer 7

σm= σ/ √n