document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1168123>Question 1168123</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose the amount of heating oil used annually by households in Ontario is normally distributed, with a mean of 760 liters per household per year and a standard deviation of 150 liters of heating oil per household per year. <BR>\n" );
document.write( "a) What is the probability that a randomly selected Ontario household uses more than 570 liters of heating oil per year?<BR>\n" );
document.write( "b) what is the probability that a randomly selected Ontario household uses between 680 and 1130 liters per year?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #792759 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=792759\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> mean is 760 liters per household.<BR>\n" );
document.write( "standard deviation is 150 liters liters per household.<BR>\n" );
document.write( "z-score = (x -m) / s\r<BR>\n" );
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document.write( "in this problem:<BR>\n" );
document.write( "m = 760<BR>\n" );
document.write( "s = 150\r<BR>\n" );
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document.write( "when x = 570, the z-score will be (570 - 760) / 150 = -1.267.<BR>\n" );
document.write( "this z-score indicates that approximately 10.56% of the households will use less than 570 liters of heating oil annually.\r<BR>\n" );
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document.write( "when x1 = 680 and x2 = 1130, z1 will be (680-760)/150 = -.533 and (1130-760)/150 = 2.47.<BR>\n" );
document.write( "those z-scores indicate that approximately 69.62% of the households will use between 680 and 1130 liters of heating oil manually.\r<BR>\n" );
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document.write( "on the normal distribution graph, these statistics look like the following.\r<BR>\n" );
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document.write( "the first graph shows the probability that a randomly selected household will consume less than 570 liters of fuel annually.\r<BR>\n" );
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document.write( "the second graph shows the probability that a randomly selected household will consume between 680 and 1130 liters of fuel annually.\r<BR>\n" );
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document.write( "the calculator that provided these results can be found at <a  rel=nofollow HREF= \"http://davidmlane.com/hyperstat/z_table.html\" target = \"_blank\">http://davidmlane.com/hyperstat/z_table.html</a>\r<BR>\n" );
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document.write( "if you are using this calculator with z-scores, then the mean is 0 and the standard deviation is 1.\r<BR>\n" );
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document.write( "results from this calculator using z-scores is shown below.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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