# Maths

The Random Variable X is normally distributed with mean 560 and standard deviation 20.

Find P(X<530) which I calculated as 0.0668.

However... Next question asks

It is known that p(|X-560|<a) = 0.6
Find the value of a

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3. 👁 67
1. using the web site I gave you, I get 16.829

check "Value from area"
enter mean and std and area=0.6
click "between"

see graph and go "Aha!"

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posted by Steve
2. So I got mean as 0 and SD as 20 and area being 0.6 and got 16.8.

How do I formulate working out step by step for this question without using online calculator

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posted by Ed
3. you have to look up values in the Z table and see what area they define. Better review how to use the table.

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2. 👎 0
posted by Steve

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