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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. 
H_(0):sigma_(1)^(2)!=sigma_(2)^(2)
B. 
H_(0):sigma_(1)^(2)=sigma_(2)^(2)

H_(1):sigma_(1)^(2)=sigma_(2)^(2)quadH_(1):sigma_(1)^(2) > sigma_(2)^(2)
C. 
H_(0):sigma_(1)^(2)=sigma_(2)^(2)
D.

{:[H_(0):sigma_(1)^(2)=sigma_(2)^(2)],[H_(1):sigma_(1)^(2)!=sigma_(2)^(2)]:}

H_(1):sigma_(1)^(2) < sigma_(2)^(2)
Identify the test statistic.

◻ (Round to two decimal places as needed.)

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 2929 people who drank ethanol and another group of 2929 people given a placebo. The errors for the treatment group have a standard deviation of 22.1010 , and the errors for the placebo group have a standard deviation of 00.8282 . Assume that the two populations are normally distributed. Use a 00.0505 significance level to test the claim that both groups have the same amount of variation among th errors.\newlineLet sample 11 be the sample with the larger sample variance, and let sample 22 be the sample with the smalle sample variance. What are the null and alternative hypotheses?\newlineA. H0:σ12σ22 H_{0}: \sigma_{1}^{2} \neq \sigma_{2}^{2} \newlineB. H0:σ12=σ22 H_{0}: \sigma_{1}^{2}=\sigma_{2}^{2} \newlineH1:σ12=σ22H1:σ12>σ22 \mathrm{H}_{1}: \sigma_{1}^{2}=\sigma_{2}^{2} \quad \mathrm{H}_{1}: \sigma_{1}^{2}>\sigma_{2}^{2} \newlineC. H0:σ12=σ22 H_{0}: \sigma_{1}^{2}=\sigma_{2}^{2} \newlineD.\newlineH0:σ12=σ22H1:σ12σ22 \begin{array}{l} H_{0}: \sigma_{1}^{2}=\sigma_{2}^{2} \\ H_{1}: \sigma_{1}^{2} \neq \sigma_{2}^{2} \end{array} \newlineH1:σ12<σ22 \mathrm{H}_{1}: \sigma_{1}^{2}<\sigma_{2}^{2} \newlineIdentify the test statistic.\newline \square (Round to two decimal places as needed.)

Full solution

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 2929 people who drank ethanol and another group of 2929 people given a placebo. The errors for the treatment group have a standard deviation of 22.1010 , and the errors for the placebo group have a standard deviation of 00.8282 . Assume that the two populations are normally distributed. Use a 00.0505 significance level to test the claim that both groups have the same amount of variation among th errors.\newlineLet sample 11 be the sample with the larger sample variance, and let sample 22 be the sample with the smalle sample variance. What are the null and alternative hypotheses?\newlineA. H0:σ12σ22 H_{0}: \sigma_{1}^{2} \neq \sigma_{2}^{2} \newlineB. H0:σ12=σ22 H_{0}: \sigma_{1}^{2}=\sigma_{2}^{2} \newlineH1:σ12=σ22H1:σ12>σ22 \mathrm{H}_{1}: \sigma_{1}^{2}=\sigma_{2}^{2} \quad \mathrm{H}_{1}: \sigma_{1}^{2}>\sigma_{2}^{2} \newlineC. H0:σ12=σ22 H_{0}: \sigma_{1}^{2}=\sigma_{2}^{2} \newlineD.\newlineH0:σ12=σ22H1:σ12σ22 \begin{array}{l} H_{0}: \sigma_{1}^{2}=\sigma_{2}^{2} \\ H_{1}: \sigma_{1}^{2} \neq \sigma_{2}^{2} \end{array} \newlineH1:σ12<σ22 \mathrm{H}_{1}: \sigma_{1}^{2}<\sigma_{2}^{2} \newlineIdentify the test statistic.\newline \square (Round to two decimal places as needed.)
  1. 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.\newlineVariance of treatment group = (2.10)2(2.10)^2\newlineVariance of placebo group = (0.82)2(0.82)^2
  2. Calculate Variances: Now, calculate the variances.\newlineVariance of treatment group = 4.414.41\newlineVariance of placebo group = 0.67240.6724
  3. Compare Variances: Since 4.414.41 is greater than 0.67240.6724, the treatment group (sample 11) has the larger variance, and the placebo group (sample 22) has the smaller variance.
  4. Formulate Hypotheses: The null hypothesis (H0H_0) always states that there is no difference, so it should state that the variances are equal.\newlineH0:σ12=σ22H_0: \sigma_1^2 = \sigma_2^2\newlineThe alternative hypothesis (H1H_1) 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.\newlineH1:σ12σ22H_1: \sigma_1^2 \neq \sigma_2^2\newlineSo, the correct hypotheses are:\newlineH0:σ12=σ22H_0: \sigma_1^2 = \sigma_2^2\newlineH1:σ12σ22H_1: \sigma_1^2 \neq \sigma_2^2
  5. Calculate F-test Statistic: To identify the test statistic, we use the F-test for variances. The formula for the F-test statistic is:\newlineF=s12s22F = \frac{s_1^2}{s_2^2}\newlinewhere s12s_1^2 is the variance of the sample with the larger variance, and s22s_2^2 is the variance of the sample with the smaller variance.
  6. Find F-test Statistic: Now, calculate the F-test statistic. F=4.410.6724F = \frac{4.41}{0.6724}
  7. Find F-test Statistic: Now, calculate the F-test statistic. \newlineF=4.410.6724F = \frac{4.41}{0.6724} Perform the division to find the F-test statistic. \newlineF6.56F \approx 6.56

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