The z-test 10.1 Assume that a treatment does have an effect and that the treatment effect is being evaluated with a z hypothesis test. If all factors are held constant, how is the outcome of the hypothesis test influenced by sample size? To answer this question, do the following two tests and compare the results. For both tests, a sample is selected from a normal population distribution with a mean of u = 32 and %3D a standard deviation of o = 11. After the treatment is administered to the individuals in the sample, the sample mean is found to be M = 35. In each case, use a two-tailed test with a = .05. For the first test, assume that the sample consists of n = 16 individuals. For the second test, assume that the sample consists of n = 64 individuals. Explain in your own words how the outcome of the hypothesis test is influenced by the sample size. а. b. с. (Note: Be sure and show a full diggram of the research design. Also show all steps and

A researcher administers a new treatment to a sample of participants selected from a population with µ = 80. If the researcher obtains a sample mean of M = 88, which combination of factors is most likely to result in rejecting the null hypothesis?

If a treatment is expected to decrease scores on a variable for which the mean is expected to be µ = 50, what is the null hypothesis?

A two-tailed hypothesis test is being used to evaluate a treatment effect with α = .05.  If the sample data produce a z-score of z = -0.43, then what is the correct decision?   a. Reject the null hypothesis and conclude that the treatment has an effect.   b.  Reject the null hypothesis and conclude that the treatment has no effect.   c. Fail to reject the null hypothesis and conclude that the treatment has no effect.   d. Fail to reject the null hypothesis and conclude that the treatment has an effect.

Below indicate whether the appropriate test would be an independent t-test, dependent t-test, One-way ANOVA, or z-test. . A statistics professor wants to know if students who turn their homework in on time get higher exam grades than students who do not turn their homework in on time.

Functional foods are those containing nutritional supplements in addition to natural nutrients. For example, orange juice with calcium. A researcher asked students to rate their general attitude towards functional foods on a 7-point scale (higher score is more positive). The results are as follow: Females Males n = 15 n = 12 M = 5 M = 4 SS = 7 SS = 8 a. Do the data indicate a significant difference in attitude for males and females? Use a two-tailed test with α = .05 b. Your alternative hypothesis in symbols is c.  The critical tvalues are d. The t-statistic is: e. Your decision is f. r2 is:

You are conducting a study to see if the proportion of men over 50 who regularly have their prostate examined is significantly different from 0.25. You use a significance level of α=0.01α=0.01.      H0:p=0.25H0:p=0.25      H1:p≠0.25H1:p≠0.25You obtain a sample of size n=687n=687 in which there are 143 successes.What is the test statistic for this sample? (Report answer accurate to three decimal places.)test statistic = What is the p-value for this sample? (Report answer accurate to four decimal places.)p-value =

Researchers investigate how the presence of cell phones influence the quality of human interaction.  Subjects are randomly selected from a population and divided into an experimental group that is asked to leave their phones in the front of the room and a control group that are not asked to leave their cell phones at the front of the room.  Subjects are left alone for 10 minutes and then asked to take a survey designed to measure quality of interactions they had with others in the experiment.  What statistical test is appropriate?

The pulse rates of 176 randomly selected adult males vary from a low of 40 bpm to a high of 116 bpm. Find the minimum sample size required to estimate the mean pulse rate of adult males. Assume that we want 95% confidence that the sample mean is within 2 bpm of the population mean.

Reject or Fail to Reject the null hypothesis. There is or is not sufficient evidence to support the claim that those treated with magnets have a greater mean reduction in pain than those given a sham treatment.