document.write( "Question 354335: A supplier contract calls for a key dimension of a part to be between 1.95 and 2.05 cm. The supplier has determined that the standard deviation of its process which is normally distributed, is 0.10 cm. \r
\n" );
document.write( "\n" );
document.write( "a. If the mean is 1.98, what fraction of parts will meet specifications?
\n" );
document.write( "b. If the mean is adjusted to 2.00, what fraction of the parts will meet specifications?
\n" );
document.write( "c. How small must the standard deviation be to ensure that no more than 2% of parts are nonconforming, assuming the mean is 2.oo? \n" );
document.write( "
Algebra.Com's Answer #253226 by stanbon(75887) ![]() You can put this solution on YOUR website! A supplier contract calls for a key dimension of a part to be between 1.95 and 2.05 cm. The supplier has determined that the standard deviation of its process which is normally distributed, is 0.10 cm. \n" ); document.write( "a. If the mean is 1.98, what fraction of parts will meet specifications? \n" ); document.write( "--- \n" ); document.write( "z(1.95) = (1.95-1.98)/0.1 = -.3000 \n" ); document.write( "z(2.05) = (2.05-1.98)/0.1 = 0.7 \n" ); document.write( "--- \n" ); document.write( "P(1.95< x <1.98) = P(-0.3 < z < 0.7) = normalcdf(-0.3,0.7) = 0.3759 \n" ); document.write( "----------------------------------------------------\r \n" ); document.write( "\n" ); document.write( "b. If the mean is adjusted to 2.00, what fraction of the parts will meet specifications? \n" ); document.write( "Same procedure as used in part a. \n" ); document.write( "----------------------------------------------------\r \n" ); document.write( "\n" ); document.write( "c. How small must the standard deviation be to ensure that no more than 2% of parts are nonconforming, assuming the mean is 2.oo? \n" ); document.write( "--- \n" ); document.write( "z-value with a left-tail of 1% and a right tail of 1% \n" ); document.write( "invNorm(0.01) = +/-2.3264 \n" ); document.write( "---- \n" ); document.write( "Solve :: \n" ); document.write( "(1.95-2)/s = -2.3264 \n" ); document.write( "s = 0.0215 \n" ); document.write( "------------------- \n" ); document.write( "(2.05-2)/s = 2.3264 \n" ); document.write( "s = 0.0215 \n" ); document.write( "-------------------------- \n" ); document.write( "====================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( " \n" ); document.write( " |