You have conducted an experiment and found that after treatment the mean of your sample was 57. The population parameters for the dependent variable are µ= 52, σ= 15. Your null hypothesis was rejected and you will use Cohen’s d to calculate the effect size. In one sentence, report the magnitude and evaluation of the effect size
You have conducted an experiment and found that after treatment the mean of your sample was...
A researcher conducted a one-sample z-test, and found a significant effect with the sample mean equaling 24 (n = 20), the population mean equaling 19, and the population standard deviation equaling 5. What is the effect size using Cohen’s d? [G&W Chp. 8] Cohen’s d equals 0.33 Cohen’s d equals 0.66 Cohen’s d equals 1.00 Cohen’s d does NOT equal any of the above values.
To test the effectiveness of a treatment, a sample of n = 36 people is selected from a normal population with mean of μ = 60. After the treatment is administered to the individuals in the sample, the sample mean is found to be M = 55. (a) If the population standard deviation is σ = 13, can you conclude that the treatment has a significant effect? Use a two-tailed test with α = 0.05. (Round your answers to two...
PLEASE help ?? A researcher conducted a single sample t-test on results of an experiment with n = 18 participants and the computed t = -2.28. What is the correct conclusion from this experiment if p < 0.05, 2-tails test is used for hypothesis testing? O A. The researcher failed to reject the null hypothesis and concluded that there is a significant treatment effect. O B. The researcher rejected the null hypothesis and concluded that there is a significant treatment...
A random sample of n - 16 scores is selecdted from a normal population with a mean of p - 50. After atreatment is administered to the individuals in the sample, the sample mean is found to be M -54 If the population standard deviation is σ-8, is the sample mean sufficient to conclude that the treatment has a significant effect? Use a two-tailed test with α-.05. (Hint: Recall that the critical value for a two-tailed test with α-.05 is...
TREATMENT DATA: 100, 120, 140, 95, 98, 115 Assuming untreated group has mean = 100, std.dev = 15 in the sampling distribution, should you reject or fail to reject the null hypothesis (p<0.05)? What is the effect size (Cohen’s d)?
You administered a survey to a sample of 401 high school sophomores and found a mean narcissism score of 91.3 with a standard deviation of 10. However, a recent study of high school seniors found that the average narcissism score was 92. Based on this prior research, test the null hypothesis that your sample of high school sophomores came from a population of high school sophomores in which the mean narcissism score is 92 against the alternative hypothesis that your...
The z-tests Help with this page is greatly appreciated. I dont understand how to show a full diagram. Thanks in advance :) 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,...
Capter question 17 Aa Aa A random sample of n 8 scores is obtained from a population with a mean of μ administered to the individuals in the sample, the sample mean is found to be M 50. After a treatment is 55. t Distribution Degrees of Freedom 21 ,250 2500 -3.0 -2.0 0.0 1.0 2.0 3.0 0:686 0.686 Assuming that the sample variance is s2 32, use a two-tailed hypothesis test with α = .05 to deter mine whether...
2. An experiment was conducted to compare five treatments for reducing fever. Thirty-five patients were randomly assigned into five treatment groups. The patients' temperatures were taken two hours after receiving the treatment, and are given below. We will test the claim that there is no difference in mean body temperature among each of the five treatment groups using a 5% significance level. Placebo Aspirin Anacin Tylenol Bufferin 98.3 96.0 97.2 95.1 96.1 98.7 96.6 97.4 95.7 96.5 98.1 95.3 96.9...
From a sample of 37 stolen watches, you find that the mean cash value is $950. The standard deviation for your sample is $90. Test the null hypothesis that your sample came from a population whose mean cash value (Mu) is $1,000 against the alternative hypothesis that Mu is different than $1,000. Use alpha = .05. Formally state the alternative and the null hypothesis for this test (3 pts) What is the critical value(s) for this test? (3 pts) Compute...