document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1048251>Question 1048251</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi there, If you could help me w/ this problem I would be very grateful for your help!\r<BR>\n" );
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document.write( "Assume the speed of vehicles along a stretch of I-10 has an approximately normal distribution with a mean of 71 mph and a standard deviation of 8 mph.\r<BR>\n" );
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document.write( "a. The current speed limit is 65 mph. What is the proportion of vehicles less than or equal to the speed limit?\r<BR>\n" );
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document.write( "b. What proportion of the vehicles would be going less than 50 mph?\r<BR>\n" );
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document.write( "Any help is appreciated, thanks!<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #663848 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=663848\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> mean of 71 mph and a standard deviation of 8 mph. <BR>\n" );
document.write( "<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;\" ><BR>\n" );
document.write( "a. P(x<= 65) = P(z <=  -6/8) =  P(z <=  -3/4)<BR>\n" );
document.write( "TI syntax is normalcdf(smaller z, larger z) <BR>\n" );
document.write( "normalcdf( ... is a command people using a TI Calculator<BR>\n" );
document.write( "use for finding the area under a standard normal curve<BR>\n" );
document.write( "between two z=values...-9999 used for the far far left z-value<BR>\n" );
document.write( "to give us what we want: area under a standard normal curve for<BR>\n" );
document.write( "a particular z-value, in this case z = -.75 (Area under the curve to left of Blue Line)<BR>\n" );
document.write( "normalcdf(-9999, -.75) = .2266  0r 22.66%<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=drawing%28400%2C200%2C-5%2C5%2C-.5%2C1.5%2C+graph%28400%2C200%2C-5%2C5%2C-.5%2C1.5%2C+0%2Cexp%28-x%5E2%2F2%29%29%2C+blue%28line%28+-.75%2C0%2C+-.75%2Cexp%28-.75%5E2%2F2%29%29%29%2Clocate%284.8%2C-.01%2Cz%29%2Clocate%284.8%2C.2%2Cz%29%2Clocate%28.4%2C-.02%2Cz%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "b . P(x<= 50) = P(z <=  -21/8)<BR>\n" );
document.write( "normalcdf(-9999, -21/8) = .0043  0r .43%<BR>\n" );
document.write( "One can use table as well to find the z-value </SPAN>\n" );
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