STA1DCT Assignment 2 Model Answers 1. Completed table is 2. (a) i. = AVERAGE (C2 : C33) or =AVERAGE (C: C) will work. ii. = STDEV.P(C2: C33) or =STDEV. P (C: C) will work. iii. = MEDIAN(C2:C33) or =MEDIAN(C:C) will work. Expression 1 = Expression D Expression 2 = Expression C Expression 3 = Expression B Expression 4 Expression E Expression 5 Expression A (b) Completed table is Movie Average Population standard deviation A Beautiful Mind 3.95 0.79 The Imitation Game 4.11 0.87 Good Will Hunting 4.14 0.78 (c) i. No, they all have the same median so it is hard to pick one. ii. 'Good Will Hunting' since it has the highest average. Median 4 4 4 iii. The small standard deviation means there is low variability in the scores so that many are high ratings. iv. 'Good Will Hunting'. The high average and low variability indicates that many raters were very happy with the movie. 3. (a) x == 1 4 (4 + 5 + 3.5 + 3.5) = 4. (b) The ordered values are 3.5, 3.5, 4, 5. Hence, the median is the average of the middle two values which is equal to (3.5 + 4)/2 = 3.75. (c) We have 32 = 4 - 4-1 1 [(4 - 4)2 + (5 - 4)2 + (3.5 - 4)2 + (3.5 - 4)2] = 1 3 × 1.5 = 0.5. Therefor, s = v0.5= 1/1/2. 4. The answer was found by 5. × 100 = 17.15% 465.2 (544.99 - 465.2) Histogram A: average = 100.8, standard deviation = 30.3 Histogram B: average = 150.1, standard deviation = 5.1 Histogram C: average = 40.0, standard deviation = 1.0 Histogram D: average = 69.5, standard deviation = 15.4 6. There are 25 values in total. So the median is the 13th ordered value. This value, the median, falls in the bin (2, 4].