document.write( "Question 1119062: A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 450450 seconds and a standard deviation of 6060 seconds. Between what times do we expect most (approximately 95%) of the boys to run the mile? \n" ); document.write( "
Algebra.Com's Answer #734514 by Boreal(15235)![]() ![]() You can put this solution on YOUR website! 95% would be a z between -1.96 and +1.96 \n" ); document.write( "z=(x-mean)/sd \n" ); document.write( "1.96=(x-450)/60 \n" ); document.write( "117.6=x-450 \n" ); document.write( "x=567.6 seconds one end and 332.4 seconds other end. \n" ); document.write( "(332.4, 567.6) units are seconds. \n" ); document.write( " |