document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1050444>Question 1050444</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose that the lifetimes of light bulbs are approximately normally distributed, with a mean of 57 hours and a standard deviation of 3.5 hours. With this&#8203; information, answer the following questions.\r<BR>\n" );
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document.write( "&#8203;(a) What proportion of light bulbs will last more than 62 hours?<BR>\n" );
document.write( "&#8203;(b) What proportion of light bulbs will last 53 hours or&#8203; less?<BR>\n" );
document.write( "&#8203;(c) What proportion of light bulbs will last between 57 and 62 hours?<BR>\n" );
document.write( "&#8203;(d) What is the probability that a randomly selected light bulb lasts less than 45 &#8203;hours?\r<BR>\n" );
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document.write( "How do I solve this using a TI calculator? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #666033 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=666033\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> &#8203;mean of 57 hours and a standard deviation of 3.5 hours.<BR>\n" );
document.write( "(a) What proportion of light bulbs will last more than 62 hours?<BR>\n" );
document.write( "TI syntax is P = normalcdf(smaller, larger, µ, &#963;)  <BR>\n" );
document.write( "P = normalcdf(62, 9999, 57, 3.5) |Note: 9999 used as placeholder for larger<BR>\n" );
document.write( "&#8203;(b) What proportion of light bulbs will last 53 hours or&#8203; less?<BR>\n" );
document.write( "P = normalcdf(-9999,53, 57, 3.5)<BR>\n" );
document.write( "&#8203;(c) What proportion of light bulbs will last between 57 and 62 hours?<BR>\n" );
document.write( "P = normalcdf(57,62, 57, 3.5)<BR>\n" );
document.write( "&#8203;(d) What is the probability that a randomly selected light bulb lasts less than 45 &#8203;hours? <BR>\n" );
document.write( "Since this is a continuous function, we have P(x < 45) = P(x &#8804; 45).<BR>\n" );
document.write( "P = normalcdf(-9999,45, 57, 3.5)<BR>\n" );
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