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

You have just read that chickens have a relatively low level of body fat. The population mean percentage of fat in a chicken is reported to be 32% with the standard deviation of 8.7%. How likely is it that you could randomly select a sample of 12 chickens from the population that would have a mean of 26% body fat or less?

Referring to question 29, the probability of making a Type II error is _________.

As N increases, decreases.

To use the z test the data _________.

What is the critical value for z for each of the following alpha levels?

Define mean of the sampling distribution of the mean.

If z obt falls within the critical region for rejection of H₀ , one can be certain H₀ is in reality false.

If the variability of the raw score population increases and N is held constant, _________.

The critical value for the z distribution using a = 0.01 2 tail is _________.

Define 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 crit = _________.

is sometimes called the standard error of the mean because each sample can be considered an estimate of the mean of the raw score population and variability between sample means occur due to errors in estimation.

The sampling distribution of a statistic _________.

Define ì _null.

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. The obtained value of the appropriate statistic for testing H 0 is _________.

The critical region for rejection of H 0 is the area under the curve that contains all the values of the statistic that fail to allow rejection of H 0 .

The sampling distribution of z is always normally distributed.

Power is independent of the magnitude of the independent variable's effect.

The mean attention span for adults in a certain village is 15 minutes with a standard deviation of 6.4. The mean of all possible samples of size 30, taken from that population equals _________.

If one draws all possible samples for various values of N from the same population of raw scores, as N increases _________.