# math

## math

• Submitted By: erre
• Date Submitted: 11/02/2014 12:40 PM
• Category: Philosophy
• Words: 2180
• Page: 9

b) A university gives credit in French language courses to students who pass a placement test. The language department wants to see if students who get credit in this way differ in their understanding of spoken French from students who actually take the French courses. Some faculty think the students who test out of the courses are better, but others argue that they are weaker in oral comprehension. Experience has shown that the mean score of students in the courses on a standard listening test is 24. The language department gives the same listening test to a sample of 40 students who passed the credit examination to see if their performance is different. ANS Method 3 z 2.44 ( P-value 1 0.9927 0.0073 Since 0.0073 0.05, we reject the null hypothesis. ANS Confidence interval EMBED Equation.3 4) Here are the Degree of Reading Power (DRP) scores for an SRS of 44 third-grade students from a suburban school district 40 26 39 14 42 18 25 43 46 27 19 47 19 26 35 34 15 44 40 38 31 46 52 25 35 35 33 29 34 41 49 28 52 47 35 48 22 33 41 51 27 14 54 45 Since 0.031 0.05, there is a strong evidence against H0. a) State the null and alternative hypotheses in words and symbols. b) Describe a Type I error and a Type II error in this situation. Which is more serious c) There are 30 chairs in your classroom. You decide to determine the breaking strength of each chair, and then to find the mean of those values. What values of x-bar would cause you to reject H0 at the 5 significance level Type II error would be more serious in this case, because allowing the company to continue the false advertising of its chairs strength could lead to injuries, lawsuits, and other serious consequences. ANS For a 95 confidence interval, z 1.960 EMBED Equation.3 We are 95 confident that the true mean number of unoccupied seats is between 11.7 and 13.3 seats. 9) A machine for inflating tires, when properly calibrated,...