document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=918930>Question 918930</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The amount of time spent by adults playing sports per day is normally disturbuted  with a mean of 4 hours and standard deviation 1.25 hours .<BR>\n" );
document.write( "a) Find the probability that a randomly selected adult plays sports for more than 5 hours per day .<BR>\n" );
document.write( "b) Find the probability that if four adults are randomly selected, their average number of 5 hours per day .<BR>\n" );
document.write( "c) Find the probability that if four adults are randomly selected , all four play sports for more than 5 hours per day . </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #557330 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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/cgi-bin/show-face.mpl?user=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=557330\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> mean of 4 hours and standard deviation 1.25 hours .<BR>\n" );
document.write( "a) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=z=blue+%28x+-+mu%29%2Fblue%28sigma%29 ALIGN=MIDDLE  ALT=\"z=blue+%28x+-+mu%29%2Fblue%28sigma%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > z(5) = 1/1.25 = .8, <BR>\n" );
document.write( "P(z > .8) = normalcdf(.8,100) = .2119 0r 21.19%<BR>\n" );
document.write( ".........<BR>\n" );
document.write( "b) n = 4,  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=z+=blue+%28x+-+mu%29%2Fblue%28sigma%2Fsqrt%28n%29%29 ALIGN=MIDDLE  ALT=\"z+=blue+%28x+-+mu%29%2Fblue%28sigma%2Fsqrt%28n%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "z(4.95) =  -.05/.625 = -.08  and z(5.05) = .08<BR>\n" );
document.write( "P(x=5) = P(z < .08) - P(z < .08)<BR>\n" );
document.write( "P(x=5) = 53.19 - 46.81 = 6.38%<BR>\n" );
document.write( "....<BR>\n" );
document.write( "c) select 4<BR>\n" );
document.write( "P(all four play > 5hr) = (.2119)^4 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );