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44 votes
44 votes
Suppose a normal distribution has a mean of 89 and a standard deviation of7. What is P(x less than or equal to 82)?A. 0.16B. 0.84C. 0.025D. 0.975

User Nick Weaver
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1 Answer

27 votes
27 votes

In order to find this probability, first let's find the value of z for this case, where:


z=(x-\mu)/(\sigma)

Using the mean = 89 and the std dev = 7, for x = 82 we have:


z=(82-89)/(7)=-1

Looking at the z-table for z = -1, we have a value of 0.1587.

So the probability of P(x<=82) is equal to 0.1587 (rounding, we have 0.16).

Therefore the correct option is A.

User Carrutherji
by
3.1k points
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