Question

1. Ms. Jackson has three sections of the course "Introduction to Statistics.” The midterm results reveal that class A has an average of 82, class B has an average of 88, and class C has an average of 92. If there were 20 students in class A, 25 students in class B, and 27 students in class C, what is the combined mean (the average for all the three classes)? Show your work. 2. In your Biology class, your final grade is based on a lab score, scores on two major tests, and your score on the final exam. There are 100 points available for each score. However, the lab score is worth 25% of your total grade, each major test is worth 20%, and the final exam is worth 35%. Compute the weighted average if you score 92 on the lab, 81 on the first major test, 93 on the second major test, and 85 on the final exam. Show your work.

Answer 1

Ang Average = sum of all the values Total number of values. Average of section A = 82, Total number of students in A = 20. Sum of all the scores of 20 students in section A Average of 'A = Total number of students 82 = Sum Sum of scores in Section A - 20x82 - 1640-70 Similarly , Average of section 'B'=88, Total strength= 25. Average of section B = Sum of all the student scores in section ß Total number of students 88 = Sum 25 Sum of scores in section 'B'= 88625=2200-2. Similarly, Average of section'c'= 92, Total strength= 27. Average of Section - 2 = Sum of all the student scores in section - Total number of students 92 = Sum - 27 Sum of Scores in Section - 'C' = 92x27 = 2484->

Total a students from the 3 classes = 25+27 +20=72 Average of all the '3' classes - Total scores from the three classes Total number of students from the '3'classes = 0 +2+@ 72 = 1640 +2200 + 2484 = 87.83 72 - 10o Mlabscore. Ans 87.83. weightage for the lab score = 25% Given hab score = 92 Since the weightage of the labscore is 25%, find 25% of 92= 25x92 = 1x92= 23e weighted weightage of first major test = 20% given score in the first major test = 8). As weight age is 20%. find 20 %. of 81 = 20 x 81 16.2 = weighted score of the first major test weightage of the second major test = 20% 100

score in the second major test = 93. finding 20 % of 93 100 *93 2 93 = 18.6= weighted score in 2- weightage of the final Enam = 35). a major test MON = 3 Score in nam = 85. na 354.99 85 - 85X85 = 3x85 => 29.75.2 weighted score in final exam. O Weighted average = Total weighted score in each store os sill section BA = 23+ 16.2 + 18.6+ 29.75 = 87.55