3

Answer all questions in the spaces provided.

1 The discrete random variable X has the following probability distribution

x 15 18 29

P(X = x) 0.2 0.7 0.1

Find P(X > 18)

Circle your answer.

[1 mark]

0.1 0.2 0.7 0.8

2 The continuous random variable Y has probability density function f ( y) where

ð1

1

yf ( y) dy ¼ 16 and ð1

1

y2f ( y) dy ¼ 1040

Find the standard deviation of Y

Circle your answer.

[1 mark]

28 32 784 1024

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Jun22/7366/2S

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