document.write( "Question 974386: Suppose that historically the final exam scores for Bus 101 follow the Normal
\n" ); document.write( "distribution with mean 70 and standard deviation 15. Use a Z table (not software)
\n" ); document.write( "to get your answers.
\n" ); document.write( "What proportion of students is expected to get 80 or greater on the exam?
\n" ); document.write( "b) What proportion of students is expected to get 45 or less on the exam?
\n" ); document.write( "c) What proportion of students is expected to get between 52 and 90 on
\n" ); document.write( "exam?
\n" ); document.write( "d) If the grading policy is to give an “A” to the top 15% of the scores, what is
\n" ); document.write( "the cutoff for an “A”?
\n" ); document.write( "e) If the grading policy is to give an “F” to the bottom 7% of the scores,
\n" ); document.write( "getting what score or less gives an “F”? \n" ); document.write( "

Algebra.Com's Answer #596298 by Boreal(15235) $\"\"$ $\"About$

You can put this solution on YOUR website!
mean=70
\n" ); document.write( "sd=15
\n" ); document.write( ">80 is >z=0.67 ;;0.253
\n" ); document.write( "45 or less is -1.67 sds or 0.0475
\n" ); document.write( "between 52 and 90 is sd -1.2 to sd 1.33 or about 0.794
\n" ); document.write( "It is about 1.04 sd or 15-16 points above the mean. That would be an 85,86.
\n" ); document.write( "It is about -1.475 SDs or about 22 points below the mean, or a 48.\r
\n" ); document.write( "\n" ); document.write( "These may be off slightly due to interpolation, but the idea is (score-mean)/sd = z -score \n" ); document.write( "

\n" );