jmaths
IB Mathematics: Applications and Interpretation SL · 13.2: Probability Distributions · 13.2.11
Probability distributions: exam review Exam review Answers
Section A: short questions
-
- (a) 0.2
- (b) 0.35
- (c) 12/19 (0.632)
-
- (a) 0.1
- (b) 5/9 (0.556)
-
- (a) \$3
- (b) −\$1; not fair
- (c) \$3
-
- (a) x = 0: 5/18 (0.278); x = 1: 5/9 (0.556); x = 2: 1/6 (0.167)
- (b) 8/9 (0.889)
- (c) 13/18 (0.722)
-
- (a) X ~ B(20, 0.08)
- (b) 0.271
- (c) 0.929
- (d) 0.212
-
- (a) E(X) = 14, Var(X) = 9.1
- (b) p = 0.3, n = 60
- (c) 0.437
-
- (a) Answers are independent; the probability of a correct guess is the same for every question
- (b) 0.0781
- (c) 0.179
-
- (a) 0.46
- (b) 59
- (c) 62
-
- (a) 81.5%
- (b) 0.0228
-
- (a) 52.7 g to 63.3 g
- (b) lower quartile 55.8 g, upper quartile 60.2 g
- (c) \(\mu = 58.8\), \(\sigma = 3.77\)
Section B: long questions
-
- (a) 0.0912
- (b) 0.750
- (c) 479
- (d) 38.2
- (e) 0.174
- (f) The items are independent of each other, and the probability is the same for each
- (g) Mean 40 is less than 2 × 22 = 44, so the model gives a large probability of a negative value
-
- (a) a + b = 0.5
- (b) a = 0.3, b = 0.2
- (c) 11/17 (0.647)
- (d) Expected profit −\$0.25; not fair
- (e) 0.279
- (f) 0.831
-
- (a) The median is near the middle of the box; the whiskers are about the same length (symmetric)
- (b) Q1 = 36.6, Q3 = 47.4
- (c) 10.8
- (d) 54.4
- (e) 52.3
- (f) \$4.06
jmaths.xyz · AI SL · 13.2.11 Unit review