document.write( "Question 329054: The time taken to install a new telephone is found to be normally distributed with a mean time equal to 60 minutes and a standard deviation of 12 minutes. The probability that the time to install a new telephone will be more than 36 minutes is \n" ); document.write( "

Algebra.Com's Answer #235797 by Fombitz(32388) $\"\"$ $\"About$

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Find the z score.
\n" ); document.write( " $\"z=%28x-mu%29%2Fsigma=%2836-60%29%2F12=-2\"$
\n" ); document.write( " $\"P%28-2%29=0.02275\"$
\n" ); document.write( "That probability is for values up to $\"x=36\"$ minutes ( $\"P%28x%3C=36%29\"$ ).
\n" ); document.write( " $\"P%28x%3C=36%29%2BP%28x%3E36%29=1\"$
\n" ); document.write( " $\"P%28x%3E36%29=1-P%28x%3C=36%29\"$
\n" ); document.write( " $\"P%28x%3E36%29=1-0.02275=0.97725\"$ \n" ); document.write( "

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