A certain counselor wants to compare mean IQ scores for two different social groups. A random sample of 12 IQ scores from group 1 showed a mean of 95 and a standard deviation of 16, while an independently chosen random sample of 16 IQ scores from group 2 showed a mean of 101 and a standard deviation of 13. Assuming that the populations of IQ scores are normally distributed for each of the groups and that the variances of these populations are equal, construct a 90% confidence interval for the difference u, - u, between the mean µ¡ of IQ scores of group 1 and the mean u, of IQ scores of group 2. Then find the lower limit and upper limit of the 90% confidence interval. Carry your intermediate computations to at least three decimal places. Round your responses to at least two decimal places. (If necessary, consult a list of formulas.) Lower limit:| Upper limit: Check Save For Later Submit Assignment ? ? 6. étv DIl FS

A light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs, model A and model B. Independent random samples of the two models were taken. Analysis of 15 bulbs of model A showed a mean lifetime of 1348 hours and a standard deviation of 81 hours. Analysis of 11 bulbs of model B showed a mean lifetime of 1351 hours and a standard deviation of 109 hours. Assume that the populations of lifetimes for each model are normally distributed and that the variances of these populations are equal. Construct a 99% confidence interval for the difference H-, between the mean lifetime u, of model A bulbs and the mean lifetime u, of model B bulbs. Then find the lower limit and upper limit of the 99% confidence interval, Carry your intermediate computations to at least three decimal places. Round your responses to at least two decimal places. (If necessary, consult a list of formulas.) Lower limit: Upper limit: Explanation Check 2021 McGraw-Hill Education. Al Rights Reserved…

A certain counselor wants to compare mean IQ scores for two different social groups. A random sample of 11 IQ scores from group 1 showed a mean of 120 and a standard deviation of 16, while an independently chosen random sample of 10 IQ scores from group 2 showed a mean of 113 and a standard deviation of 14. Assuming that the populations of IQ scores are normally distributed for each of the groups and that the variances of these populations are equal, construct a 90% confidence interval for the difference u,-, between the mean u, of IQ scores of group 1 and the mean u, of IQ scores of group 2. Then find the lower limit and upper limit of the 90% confidence interval. Carry your intermediate computations to at least three decimal places. Round your responses to at least two decimal places. (If necessary, consult a list of formulas.) Lower limit: Upper limit: Explanation Check 02021 McGraw H Education. All Rights Reserved Terms of UseI PivcyI Accessibty MacBook Air ese 888 %23 2$ & 3 8 Q E…

A psychology graduate student wants to test the claim that there is a significant difference between the IQs of spouses. To test this claim, she measures the IQs of 9 married couples using a standard IQ test. The results of the IQ tests are listed in the following table. Using a 0.10 level of significance, test the claim that there is a significant difference between the IQs assuming that the population distribution of the paired differences is approximately normal. Let the spouse 1 group be Population 1 and let the spouse 2 group be Population 2. Spouse 1 Spouse 2 IQs of Married Couples 124 113 97 123 121 101 128 116 96 126 119 100 Copy Data Step 2 of 3: Compute the value of the test statistic. Round your answer to three decimal places. 124 111 127 113 107 111

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

A statistics teacher taught a large introductory statistics class, with 500 students having enrolled over many years. The mean score over all those students on the first midterm was u = 88 with standard deviation o = 10. One year, the teacher taught a %3D much smaller class of only 25 students. The teacher wanted to know if teaching a smaller class was more effective and students performed better. We can consider the small class as an SRS of the students who took the large class over the years. The average midterm score was = 78. The hypothesis should be: a. Ho: H = 78 vs. Ha: H = 88. %3D O b. Ho: µ = 88 vs. Ha: µ 78 %3D Ο d. Ho: μ-88 νs. Ha: μ >88. %3D

A drug which is used for treating diabetes has potentially dangerous side effects if it is taken in doses which are larger than the required dosage for the treatment. A medical researcher believes that the variance in dosage is different for two tablets made by different production facilities. The sample variance of a sample of 11 dosages of tablet "A" is 0.013 . The sample variance of a sample of 28 dosages of tablet "B" is 0.01 . Construct the 90% confidence interval for the ratio of the population variances. Round your answers to four decimal places.

A light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs, model A and model B. Independent random samples of the two models were taken. Analysis of 10 bulbs of model A showed a mean lifetime of 1347 hours and a standard deviation of 92 hours. Analysis of 13 bulbs of model B showed a mean lifetime of 1380 hours and a standard deviation of 111 hours. Assume that the populations of lifetimes for each model are normally distributed and that the variances of these populations are equal. Construct a 95% confidence interval for the difference −μ1μ2 between the mean lifetime μ1 of model A bulbs and the mean lifetime μ2 of model B bulbs. Then find the lower limit and upper limit of the 95% confidence interval. Carry your intermediate computations to at least three decimal places. Round your responses to at least two decimal places. Upper Limit Lower Limit:

A certain counselor wants to compare mean IQ scores for two different social groups. A random sample of 15 IQ scores from group 1 showed a mean of 117 and a standard deviation of 17 , while an independently chosen random sample of 9 IQ scores from group 2 showed a mean of 112 and a standard deviation of 15 . Assuming that the populations of IQ scores are normally distributed for each of the groups and that the variances of these populations are equal, construct a 90% confidence intervalfor the difference −μ1μ2 between the mean μ1 of IQ scores of group 1 and the mean μ2 of IQ scores of group 2 . Then find the lower limit and upper limit of the 90% confidence interval. Carry your intermediate computations to at least three decimal places. Round your responses to at least two decimal places. (If necessary, consult a list of formulas.)

A certain IQ test is known to have a population mean of 100 and standard deviation of 15 in the general population. You want to test whether psychology majors have a different average IQ than the population as a whole. Assume the variance of IQ is the same for Psych majors as it is in the general population. Suppose that Psychology majors actually have an average IQ of 108. If you do a 2-tailed test at α= .05 with a sample of 56 Psychology majors, you will be able to reject the null hypothesis if the mean IQ of your sample is below [L] or above [H]. Find L and H values. Options listed below. [L] answer choices: 96.08, 98.00, 103.92, 104.08, 110.00, 111.92. [H] Answer choices:  96.08, 98.00, 103.92, 104.08, 110.00, 111.92.