document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1058647>Question 1058647</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A research concludes that the number of hours of exercise per week for adults is normally distributed with a mean of 3.5 hours and a standard deviation of 3 hours. Show all work. Just the answer, without supporting work, will receive no credit.<BR>\n" );
document.write( "(a) Find the 80th percentile for the distribution of exercise time per week. (round the answer to 2 decimal places)<BR>\n" );
document.write( "(b) What is the probability that a randomly selected adult has more than 7 hours of exercise per week? (round the answer to 4 decimal places) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #673737 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=673737\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A research concludes that the number of hours of exercise per week for adults is normally distributed with a mean of 3.5 hours and a standard deviation of 3 hours. Show all work. Just the answer, without supporting work, will receive no credit.<BR>\n" );
document.write( "(a) Find the 80th percentile for the distribution of exercise time per week. (round the answer to 2 decimal places)<BR>\n" );
document.write( "sample mean:: 3.5<BR>\n" );
document.write( "ME = 1.282*3 = 3.845<BR>\n" );
document.write( "80% CI:: 3.5-3.845 < u < 3.5+3.845<BR>\n" );
document.write( "80% CI: -0.345 < u < 7.345<BR>\n" );
document.write( "-----------------------------------------<BR>\n" );
document.write( "(b) What is the probability that a randomly selected adult has more than 7 hours of exercise per week? (round the answer to 4 decimal places) <BR>\n" );
document.write( "z(7) = (7-3.5)/3 = 3.5/3 = 1.167<BR>\n" );
document.write( "---<BR>\n" );
document.write( "P(x > 7) = P(z > 1.167) = normalcdf(1.167,100) = 0.1217<BR>\n" );
document.write( "------------<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "--------------- </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );