document.write( "Question 315070: The time to wait for a particular rural bus is distributed unifromly from 0 to 75 minutes. 100 riders are randomly sampled to learn how long they waited.\r
\n" ); document.write( "\n" ); document.write( "What is the 90th percentile sample average wait time (in minutes) for a sample of 100 riders?\r
\n" ); document.write( "\n" ); document.write( "mean = 0+75/2 = 37.5\r
\n" ); document.write( "\n" ); document.write( "I think I enter the numbers into my scientific calculator under distribution and inverse normal ( percentile, mean, stand dev. / square root of 100) or (.90, 37.5, ?)?? I can't figure out how to get the standard deviation....thank you thank you thank you
\n" ); document.write( "

Algebra.Com's Answer #225395 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
The time to wait for a particular rural bus is distributed unifromly from 0 to 75 minutes. 100 riders are randomly sampled to learn how long they waited.
\n" ); document.write( "What is the 90th percentile sample average wait time (in minutes) for a sample of 100 riders?
\n" ); document.write( "mean = 0+75/2 = 37.5
\n" ); document.write( "I think I enter the numbers into my scientific calculator under distribution and inverse normal ( percentile, mean, stand dev. / square root of 100) or (.90, 37.5, ?)??
\n" ); document.write( "-------------------------
\n" ); document.write( "I can't figure out how to get the standard deviation....
\n" ); document.write( "Comment: Please consider this. The range of the data is generally
\n" ); document.write( "considered to 6sigma. Your data range is 0 to 75.
\n" ); document.write( "If 6sigma = 75, sigma = 12.5
\n" ); document.write( "================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "
\n" ); document.write( "
\n" );