document.write( "Question 629305: 2. The average commute time via train from the Chicago O'Hare Airport to downtown is 60 minutes with a standard deviation of 15 minutes. Assume that the commute times are normally distributed. What proportion of commutes would be:
\n" ); document.write( " c. between 45 and 75 minutes? \n" ); document.write( "
Algebra.Com's Answer #396167 by ewatrrr(24785)\"\" \"About 
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document.write( "Hi
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document.write( "average commute time via train from the Chicago O'Hare Airport to downtown is 60 minutes with SD =  15 minutes
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document.write( "Assume that the commute times are normally distributed. 
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document.write( "What proportion of commutes would be: between 45 and 75 minutes? 68.2%
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document.write( " \"z+=+%2845-60%29%2F15+=+-15%2F15+=+-1\"  and \"z+=+%2875-60%29%2F15+=+15%2F15+=+1\"\r
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document.write( "For the normal distribution: 
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document.write( "one  standard deviation from the mean accounts for about 68.2% of the set ****
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document.write( "two standard deviations from the mean account for about 95.4%
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document.write( "and three standard deviations from the mean account for about 99.7%.\r
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document.write( "Important to Understand z -values as they relate to the Standard Normal curve:
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document.write( "Below:  z = 0, z = ± 1, z= ±2 , z= ±3 are plotted.  
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document.write( "Note: z = 0 (x value the mean) 50% of the area under the curve is to the left and 50%  to the right
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