Researchers conducted an experiment to test the effects of alcohol. Errors were recorded in a test of visual and motor skills for a treatment group of 29 people who drank ethanol and another group of 29 people given a placebo. The errors for the treatment group have a standard deviation of 2.10 , and the errors for the placebo group have a standard deviation of 0.82 . Assume that the two populations are normally distributed. Use a 0.05 significance level to test the claim that both groups have the same amount of variation among th errors.Let sample 1 be the sample with the larger sample variance, and let sample 2 be the sample with the smalle sample variance. What are the null and alternative hypotheses?A. H0:σ12=σ22B. H0:σ12=σ22H1:σ12=σ22H1:σ12>σ22C. H0:σ12=σ22D.H0:σ12=σ22H1:σ12=σ22H1:σ12<σ22Identify the test statistic.□ (Round to two decimal places as needed.)
Q. Researchers conducted an experiment to test the effects of alcohol. Errors were recorded in a test of visual and motor skills for a treatment group of 29 people who drank ethanol and another group of 29 people given a placebo. The errors for the treatment group have a standard deviation of 2.10 , and the errors for the placebo group have a standard deviation of 0.82 . Assume that the two populations are normally distributed. Use a 0.05 significance level to test the claim that both groups have the same amount of variation among th errors.Let sample 1 be the sample with the larger sample variance, and let sample 2 be the sample with the smalle sample variance. What are the null and alternative hypotheses?A. H0:σ12=σ22B. H0:σ12=σ22H1:σ12=σ22H1:σ12>σ22C. H0:σ12=σ22D.H0:σ12=σ22H1:σ12=σ22H1:σ12<σ22Identify the test statistic.□ (Round to two decimal places as needed.)
Identify Variances: First, we need to identify which sample has the larger variance. Since the standard deviation is the square root of the variance, we square the standard deviations to find the variances.Variance of treatment group = (2.10)2Variance of placebo group = (0.82)2
Calculate Variances: Now, calculate the variances.Variance of treatment group = 4.41Variance of placebo group = 0.6724
Compare Variances: Since 4.41 is greater than 0.6724, the treatment group (sample 1) has the larger variance, and the placebo group (sample 2) has the smaller variance.
Formulate Hypotheses: The null hypothesis (H0) always states that there is no difference, so it should state that the variances are equal.H0:σ12=σ22The alternative hypothesis (H1) is what we are trying to prove. Since we are testing for equality and not a specific direction, it should state that the variances are not equal.H1:σ12=σ22So, the correct hypotheses are:H0:σ12=σ22H1:σ12=σ22
Calculate F-test Statistic: To identify the test statistic, we use the F-test for variances. The formula for the F-test statistic is:F=s22s12where s12 is the variance of the sample with the larger variance, and s22 is the variance of the sample with the smaller variance.
Find F-test Statistic: Now, calculate the F-test statistic. F=0.67244.41
Find F-test Statistic: Now, calculate the F-test statistic. F=0.67244.41 Perform the division to find the F-test statistic. F≈6.56
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