Analysis and Approaches for IBDP Maths Ebook 1 | Page 286

Your Practice Set – Analysis and Approaches for IBDP Mathematics
3. A random variable X is distributed normally with a mean of 30 and standard deviation
of 4.
(a) On the following diagram, shade the region representing P(23.5 � X � 30) .
[2]
(b) Write down P(23.5 � X � 30) , correct to four decimal places.
(c) Let P(30 � X � c) � 0.2 . Write down the value of c .
[2]
[2]
4. A random variable X is distributed normally with a mean of 162 and standard deviation
of 8.
(a) On the following diagram, shade the region representing P(162 � X � 171) .
[2]
(b) Write down P(162 � X � 171) , correct to four decimal places.
(c) Let P( c� X �162) � 0.19 . Write down the value of c .
[2]
[2]
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