Date | November 2016 | Marks available | 2 | Reference code | 16N.1.hl.TZ0.2 |
Level | HL only | Paper | 1 | Time zone | TZ0 |
Command term | Find | Question number | 2 | Adapted from | N/A |
Question
The faces of a fair six-sided die are numbered 1, 2, 2, 4, 4, 6. Let X be the discrete random variable that models the score obtained when this die is rolled.
Complete the probability distribution table for X.
[2]
a.
Find the expected value of X.
[2]
b.
Markscheme
A1A1
Note: Award A1 for each correct row.
[2 marks]
a.
E(X)=1×16+2×13+4×13+6×16 (M1)
=196 (=316) A1
Note: If the probabilities in (a) are not values between 0 and 1 or lead to E(X)>6 award M1A0 to correct method using the incorrect probabilities; otherwise allow FT marks.
[2 marks]
b.
Examiners report
[N/A]
a.
[N/A]
b.
Syllabus sections
Topic 5 - Core: Statistics and probability » 5.5 » Concept of discrete and continuous random variables and their probability distributions.
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