document.write( "Question 626447: Mrs. Jones Algebra 2 class scored very well on yesterday’s quiz. With one exception, everyone received an A. Within how many standard deviations from the mean do all the quiz grades fall? \r
\n" ); document.write( "\n" ); document.write( "91, 92, 94, 88, 96, 99, 91, 93, 94, 97, 95, 97\r
\n" ); document.write( "\n" ); document.write( "A. 2
\n" ); document.write( "
\n" ); document.write( "B. 1
\n" ); document.write( "
\n" ); document.write( "C. 3
\n" ); document.write( "
\n" ); document.write( "D. 4
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #394262 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!

\n" ); document.write( "

 
\n" );
document.write( "Hi,
\n" );
document.write( "Mrs. Jones Algebra 2 class scored very well on yesterday’s quiz: 91, 92, 94, 88, 96, 99, 91, 93, 94, 97, 95, 97 
\n" );
document.write( "With one exception, everyone received an A. Within how many standard deviations from the mean do all the quiz grades fall? 
\n" );
document.write( "Mean =  93.9 , SD = 3.12  (Using Excel Data Analysis Tool)
\n" );
document.write( " (99-93.9)/3.12 = 1.6 
\n" );
document.write( " (88 - 93.9)/3.12 = -1.89
\n" );
document.write( "all the quiz grades fall within 2 SD from the mean.
\n" );
document.write( "Important to Understand z -values as they relate to the Standard Normal curve:
\n" );
document.write( "Below:  z = 0, z = ± 1, z= ±2 , z= ±3 are plotted.  
\n" );
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
\n" );
document.write( "\r
\n" );
document.write( "\n" );
document.write( "  \n" );
document.write( "

\n" );