document.write( "Question 871457: If anyone can help me answering this question would be greatly appreciated \r
\n" ); document.write( "\n" ); document.write( "The speed of all cars traveling on a highway is normally distributed with a mean of 68 miles per hour and a standard deviation of 3 miles per hour. Find the probability that the mean speed of random sample of 16 cars traveling on the highway is:\r
\n" ); document.write( "\n" ); document.write( "a) less than 66mph\r
\n" ); document.write( "\n" ); document.write( "b) more than 69mph\r
\n" ); document.write( "\n" ); document.write( "c) between 67 and 69mph \n" ); document.write( "

Algebra.Com's Answer #525633 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!


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document.write( "Hi
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document.write( "m = 68mph, SD = 3,  s = 3/sqrt(16) = 3/4
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document.write( "sample 16 
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document.write( "a) P(xbar < 66mph), z = -2/(3/4) = -8/3 = -2.6667
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document.write( "P(z < -2.6667) = .0038   0r  .38%
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document.write( "b)P(xbar > 69mph), z = 1/(3/4) = 4/3
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document.write( "P(z > 1.3333) = .0912   0r 9.12%
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document.write( "P( 67 < xbar <69 ) = .9088 - .0912 = .8976   0r 89.76%
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document.write( "0r P( 67 < xbar <69 )= normalcdf(67, 69, 68, .75) \n" );
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