document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=209683>Question 209683</A>: <I><SPAN STYLE=\"word-break: break-all;\">  Story problems always confuse me.  I have tried and tried to get this one, and I can't do it. Can some one please help me?\r<BR>\n" );
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document.write( "The 1990 life expectancy of males in a certain country was 71.3 years. In 1995, it was 74.5 years.  Let E represent the life expectancy in year t and let t represent the number of years since 1990.\r<BR>\n" );
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document.write( "The linear function E(t) that fits the data is\r<BR>\n" );
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document.write( "E(t) = ___t  + ___ (round to the nearest tenth)\r<BR>\n" );
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document.write( "Use the function to predict the life expectancy in males in 2006\r<BR>\n" );
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document.write( "E(16) = ____ (round to the nearest tenth) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #158522 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=158522\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The 1990 life expectancy of males in a certain country was 71.3 years. In 1995, it was 74.5 years. Let E represent the life expectancy in year t and let t represent the number of years since 1990.<BR>\n" );
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document.write( "You have two points relating year and life expectancy: (0,71.3)and(5,74.5)<BR>\n" );
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document.write( "slope = (74.5-71.3)/(5-0) = 3.2/5 = 0.64<BR>\n" );
document.write( "intercept: when t = 0, expected life = 71.3<BR>\n" );
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document.write( "The linear function E(t) that fits the data is <BR>\n" );
document.write( "E(t) = 0.64t + 71.3 (round to the nearest tenth)<BR>\n" );
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document.write( "Use the function to predict the life expectancy in males in 2006 <BR>\n" );
document.write( "E(16) = 0.64*16 + 71.3 (round to the nearest tenth)<BR>\n" );
document.write( "E(16) = 81.54 yrs.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "Reply to stanbon@comcast.net </SPAN>\n" );
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