document.write( "Question 74581: Given a normal distribution with µ = 100 and σ = 10, if you select a sample of n = 25, what is the probability that X bar is
\n" );
document.write( "a. less than 95?
\n" );
document.write( "b. Between 95 amd 97.5?
\n" );
document.write( "c. Above 102.2?
\n" );
document.write( "d. There is a 65% chance that X bar is above what value?
\n" );
document.write( " \n" );
document.write( "
Algebra.Com's Answer #53552 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! Given a normal distribution with µ = 100 and sigma = 10, if you select a sample of n = 25, what is the probability that X bar is \n" ); document.write( "a. less than 95? \n" ); document.write( "z(95) = (95-100)/10/sqrt25) = -5/2 = -2.5 \n" ); document.write( "P(xbar<95)=P(z<-2.5)=0.006 \n" ); document.write( "------------- \n" ); document.write( "b. Between 95 amd 97.5 \n" ); document.write( "z(95)=-2.5 ; z(97.5) = (97.5-100)/10/5=-2.5/2=-1.25 \n" ); document.write( "P(95 \n" ); document.write( "c. Above 102.2? \n" ); document.write( "z(102.2)=(102.2-100)/2=1.1 \n" ); document.write( "P(xbar>102.2)=P(z>1.1)=0.135666... \n" ); document.write( "--------------- \n" ); document.write( "d. There is a 65% chance that X bar is above what value? \n" ); document.write( "The corresponding z-value is z=-0.38532... \n" ); document.write( "Converting to raw score: -0.38532 = (xbar-100)/2; \n" ); document.write( "xbar=2*(-0.38532)+100 \n" ); document.write( "xbar=99.23 \n" ); document.write( "------------- \n" ); document.write( "====================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( " |