Exam 12: Sampling Distributions, Sampling Distribution of the Mean: the Normal Deviate Z Test

A health psychologist knows the smoking population at the hospital where she works smokes an average of 18 cigarettes per day with a standard deviation of 7. She plans to conduct a program to reduce smoking. If she has 25 persons in her program, what is the power to detect a real effect of the program such that cigarette consumption is reduced, on the average, by 5 cigarettes? Assume population normality and use a = 0.05 1 tail .

If z obt had a value of 4.50 in the direction opposite from that predicted by the directional H ₁ and z crit was 2.58, one would _________.

Using the sample standard deviation as an estimate for the population standard deviation is an example of interval estimation.

Alpha and Beta are inversely related.

The sampling distribution of the mean changes as sample size changes.

As sample size increases, _________.

Power and Beta are directly related.

In problem 27, if you were testing the hypothesis that the sample mean (108) was drawn from the Null Hypothesis Population with µ = 100 and s = 15, what would you conclude using a = 0.05 1 tail ?

If we are to use the statistic for inference, why is it important to know the sampling distribution of a statistic?

To use the z test, _________.

Define ì _real.

If the sample mean is different from the population mean, H₀ must be false.

The sampling distribution of the mean _________.

A set of sample scores from an experiment has an N = 28 and a mean = 52. H 1 is directional, predicting an effect of the independent variable which decreases the magnitude of the dependent variable. H 0 asserts the sample is a random sample from a population of scores where µ = 55 and s = 12. a = 0.05_{1 tail}. Using the z test to analyze the data, z obt = _________.

Define standard error of the mean.

An English teacher has been teaching a sixth grade composition class for many years. He has the feeling that over the past several years, the writing ability of students has changed. A national test of proficiency in composition was administered 5 years ago. The resulting distribution of scores was normally shaped, had a mean of 85 and a standard deviation of 10.9. In order to test his feeling, he gives his present class of 43 students the same proficiency test. The resulting mean is 80 and the standard deviation is 8.7. Using the z test with a = 0.05 2 tail , what is your conclusion?

The sampling distribution of the mean gives _________.

From a population of 4 different scores (e.g. 3, 5, 7, 9) how many samples of size N = 2 are possible sampling one at a time with replacement? (Solve by enumeration.)

In general, Alpha + Beta = 1.

The symbol for the standard error of the mean is .