SOLUTION: Students who have completed a speed reading course have reading speeds that are normally distributed with a mean of 950 words per minute and a standard deviation equal to 220 words

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Question 623218: Students who have completed a speed reading course have reading speeds that are normally distributed with a mean of 950 words per minute and a standard deviation equal to 220 words per minute. If two students were selected at random, what is the probability that they would both read at less than 400 words per minute?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

Students who have completed a speed reading course have reading speeds 

that are normally distributed with a mean of 950 words per minute and a standard deviation equal to 220 words per minute. 

P( x < 400) = P(z < -550/220) = p( z < -2.5) = .006  | Using Excel function NORMSDIST(-2.5)

If two students were selected at random, 

P(both read < 400 words per minute) = .006%2A.006