document.write( "Question 685934: Given a normal distribution with µ = 100 and σ = 10, if you select a sample of n = 25, what is the probability that x¯ is:
\n" ); document.write( "a. less than 47?
\n" ); document.write( "b. between 95 and 97.5?
\n" ); document.write( "c. above 102.2?
\n" ); document.write( "d. there is a 65% chance that x¯ is above what value?
\n" ); document.write( "

Algebra.Com's Answer #424667 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
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 47?
\n" ); document.write( "z(47) = (47-100)/[10/sqrt(25)] = -52/2 = -26
\n" ); document.write( "P(x-bar < 47) = P(z < -26) is very close to zero.
\n" ); document.write( "----------------------------------------------------\r
\n" ); document.write( "\n" ); document.write( "b. between 95 and 97.5?
\n" ); document.write( "Find the z-value corresponding to 95 and 97.57
\n" ); document.write( "Find the Probability between those z values.
\n" ); document.write( "------------------------------------------------------
\n" ); document.write( "c. above 102.2?
\n" ); document.write( "Find the z-value of 102.2
\n" ); document.write( "Find the probability that z is above that z-value.
\n" ); document.write( "------------------------------------------------------
\n" ); document.write( "d. there is a 65% chance that x-bar is above what value?
\n" ); document.write( "Find the z-value with a left tail of 0.35
\n" ); document.write( "invNorm(0.35) = -0.3853
\n" ); document.write( "Find the x-bar value using x-bar = z*s + u
\n" ); document.write( "-------
\n" ); document.write( "x-bar = -0.3853*2+100 = 99.23
\n" ); document.write( "=====================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "========\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );