A sample is selected from a population with population mean = 50. After a treatment is administered to the individuals in the sample, the mean is found to be M = 55 and the variance is s2 = 64. a.  If the sample has n = 36 scores, then conduct the four steps of hypothesis testing to evaluate the significance of the treatment effect and calculate Cohen’s d to measure the size of the treatment effect. Use a two-tailed test with alpha level = .05.

20% of all college students volunteer their time. Is the percentage of college students who are volunteers smaller for students receiving financial aid? Of the 356 randomly selected students who receive financial aid, 61 of them volunteered their time. What can be concluded at the αα = 0.10 level of significance? For this study, we should use? Select an answer z-test for a population proportion? or t-test for a population mean?         The null and alternative hypotheses would be:             H0:H0:? μ or  p  Select an answer ≥ = < > ≤ ≠   _______(please enter a decimal)          H1:H1:? μ  or  p  Select an answer ≥ ≠ = < > ≤   _______ (Please enter a decimal)        2. The test statistic ? t  or z  = ______ (please show your answer to 3 decimal places.)           The p-value = ______ (Please show your answer to 4 decimal places.)           The p-value is ? >  or  ≤  α         3. Based on this, we should Select an answer fail to reject? reject ? accept ? the null…

Use the t-distribution and the sample results to complete the test of the hypotheses. Use a 5% significance level. Assume the results come from a random sample, and if the sample size is small, assume the underlying distribution is relatively normal.Test H0 : μ=15 vs Ha : μ>15 using the sample results x¯=17.2, s=6.4, with n=40. Give the test statistic and the p-value. What is the conclusion?

A nutritionist wants to investigate whether her new diet will be effective in helping women aged 30-40 to lose weight. She will use a paired sample to determine whether the mean weight of women before going on this diet is greater than the mean weight of women after being on this diet for two months. Determine the null and alternative hypotheses for the proposed hypothesis test. O A. Let μ₁ denote the mean weight of women before going on this diet and let μ₂ denote the mean weight of women who have been on this diet for two months. The null and alternative hypotheses are Ho: H₁ H2 and Ha: H₁ H₂. O D. Let μ₁ denote the mean weight of women before going on this diet and let μ₂ denote the mean weight of women who have been on this diet for two months. The null and alternative hypotheses are Ho: H₁ H2 and Ha: H₁ H₂.

A sample of n=4 scores has ΣX=8 and ΣX2=40. What is the value of the sample variance, s2?​

To evaluate the effect of a treatment, a sample of n=6 is obtained from a population with a mean of µ=80, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M=72. a. If the sample variance is s²=54, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with α=.05? b. If the sample variance is s²=150, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with α=.05? c. Comparing your answers for parts a and b, how does the variability of the scores in the sample influence the outcome of the hypothesis test?

14% of all Americans suffer from sleep apnea. A researcher suspects that a lower percentage of those who live in the inner city have sleep apnea. Of the 359 people from the inner city surveyed, 43 of them suffered from sleep apnea. What can be concluded at the level of significance of αα = 0.05? For this study, we should use Select an answer z-test for a population proportion t-test for a population mean  The null and alternative hypotheses would be:     Ho: ? μ p  Select an answer = ≠ > <   (please enter a decimal)    H1: ? p μ  Select an answer < > = ≠   (Please enter a decimal) The test statistic ? t z  =  (please show your answer to 3 decimal places.) The p-value =  (Please show your answer to 4 decimal places.) The p-value is ? > ≤  αα Based on this, we should Select an answer reject fail to reject accept  the null hypothesis. Thus, the final conclusion is that ... The data suggest the populaton proportion is significantly smaller than 14% at αα = 0.05, so…

Use the t-distribution and the sample results to complete the test of the hypotheses. Use a 5% significance level. Assume the results come from a random sample, and if the sample size is small, assume the underlying distribution is relatively normal.Test H0 : μ=4 vs Ha : μ≠4 using the sample results x¯=4.8, s=2.3, with n=15.     Give the test statistic and the p-value.   What is the conclusion?

After conducting your one-sample z-test, you find an obtained z-statistic of 1.08 and a critical z-statistic of 1.64.  What do you conclude? Group of answer choices Fail to reject the null hypothesis; the sample mean and population mean are significantly different. Reject the null hypothesis; the sample mean and population mean are significantly different. Fail to reject the null hypothesis; the sample mean and population mean are not significantly different. The results of the test are inconclusive.

To evaluate the effect of a treatment, a sample of n = 8 is obtained from a population with a mean of μ = 40, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M = 35. (Use the 4-step procedure to conduct the hypothesis test)  If the sample variance is s2 = 32, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with α = .05? If the sample variance is s2 = 72, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with α = .05? Comparing your answer for parts a and b, how does the variability of the scores in the sample influence the outcome of a hypothesis test?