Research Methods and Statistics Midterm Exam Essays

Research Methods and Statistics Midterm Exam Essays Research Methods and Statistics Midterm Exam Essay Research Methods and Statistics Midterm Exam Essay In the formula n Is the sample size. Median position = (n + 2 Median position = (24 + 1)/2 Median position = 25/2 = 12. 5 Now we look for position 12 and 13. Position 12 is 5, and position 13 is 6. We take the average of the two values and that is the median. Median = (5 11/2= 5. 5 Median = 5. 5 The mode is the most frequent response in the distribution 6-1 2-2 7-2 3-6 8-6 4?2 5-1 10-1 In this example we have two modes. They are 3 and 8. A creativity test. The student scored 123 on the intelligence test and 123 on the creativity test. The mean for the intelligence test is 100, and the standard deviation is 16. The mean for the creativity test is 115, and the standard deviation is 14. What statistic would you use to compare the two scores from these two different distributions (the intelligence test distribution and the creativity test distribution)? Compute this statistic and determine on which test, if either, the student performed better. Explain your answer. (10 pets) Intelligence test score = 123, mean = 100, tankard deviation = 16 Creativity test score = 123, mean = 1 15, standard deviation = 14 To determine on which test the student did better, we use the standard deviation and the mean. To do the determination we have to use the standard deviation in proportion to the normal curve. Intelligence 129 Creativity Range: 84- 116 101 The student did better in the intelligence test since the mean for both test is within the range for the intelligence test. 3) a. Calculate the standard deviation for the following distribution: (5 pets total) calculate the mean (1+2+3+7+8+9) = 30 / 6 = 5 Subtract the mean from each score 1 -5=-4 7-5=2 2-5=-3 8-5=3 Square the resulting difference for each score. These are the squared deviations. -4 X -4 = 16 -3 x-3=9 EX.=9 -2 x-2=4 4 X 4=16 Add the squared deviations. (16+9+4 +4+9+ 16) = 58 Divide the squared deviations by the sample size to get the variance. 58 / 6 Take the square foot of the variance to get the standard deviation. Standard deviation = 3. 11 = 9. 67 -7=0 2-7=-5 8-7=1 3-7 9-7=2 Square the difference -6 x -6=36 OX=O -5 x -5=25 XIX- -4 x -4=16 ex.=4 Add the squared deviations and divide by the sample size 36 +25+16+0+1 Take the square foot of the variance = 3. 9 = 3. 7 c. What percentage of people would have scores falling between the mean and this value? 13. 66% d. What percentage of people would have scores falling at or below this value? 27. 32% 4) Sally was given a standardized test in which the mean for her class was 500, and the standard deviation was 100. Sally scored 400. Compute her score to a z-score (show your work). How did Sally perform relative to the rest of her class (be specific)? (10 pets) z = (400-500) 1100 z100/100 z