Psyc354: Distribution of Sample Means

According to the central limit theorem, the standard error for the distribution of sample means becomes smaller as the sample size decreases.

F

If the sample size is increased, then the standard error for sample means also increases.

F

Which statement below is not consistent with the distribution of sample means?

The distribution of sample means tends to pile up around the population standard deviation.

A random sample of n = 4 scores is obtained from a normal population with µ = 30 and σ = 8. What is the probability that the sample mean will be less than M = 22?

p = 0.0228

When a sample size from a population is n = 1, then the standard error will always equal the _____.

population standard deviation

A sample of n = 64 scores is selected from a population with µ= 80 with σ = 24. On average, how much error is expected between the sample mean and the population mean?

3 points

If random samples, each with n = 16 scores, are selected from a normal population with µ = 100 and σ = 20, how much difference, on average, should there be between a sample mean and the population mean?

5 points

A sample of n = 100 scores is selected from a normal population with µ= 75 and σ = 11. The probability of obtaining a sample mean greater than M = 78 is p = 0.0032.

T

As the population standard deviation increases, the standard error will also increase.

T

Standard error allows sampling error to be defined and measured.

T

The standard error equation can be rewritten to √(σ2/n).

T

Which is the expected value of M?

the mean of the distribution of sample means

Which is the standard error of M?

the standard deviation of the distribution of sample means

A sample of n = 64 scores is selected from a population with µ= 60 and σ = 10. If the sample mean is M = 57, what is the z-score for this sample mean?

z = -2.40

Samples of size n = 9 are selected from a normal population with µ= 80 with σ = 18. What is the standard error for the distribution of sample means?

σM = 6