document.write( "Question 1202778: In New York State, the mean salary for high school teachers in 2017 was $105,410 with a standard deviation of $9,680. Only Alaska’s mean salary was higher! Assume New York’s state salaries follow a normal distribution.\r
\n" ); document.write( "\n" ); document.write( "a. What percent of New York’s state high school teachers earn between $90,000 and $95,000?
\n" ); document.write( "b. What percent of New York’s state high school teachers earn between $95,000 and $110,000?
\n" ); document.write( "c. What percent of New York’s state high school teachers earn less than $80,000?
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Algebra.Com's Answer #837877 by ikleyn(52874)\"\" \"About 
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\n" ); document.write( "In New York State, the mean salary for high school teachers in 2017 was $105,410 with a standard deviation of $9,680.
\n" ); document.write( "Only Alaska’s mean salary was higher! Assume New York’s state salaries follow a normal distribution.
\n" ); document.write( "(a) What percent of New York’s state high school teachers earn between $90,000 and $95,000?
\n" ); document.write( "(b) What percent of New York’s state high school teachers earn between $95,000 and $110,000?
\n" ); document.write( "(c) What percent of New York’s state high school teachers earn less than $80,000?
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\n" ); document.write( "\n" ); document.write( "        The major starting point in solving this and many other similar problems is that
\n" ); document.write( "        the wording description only DISTRACTS your attention.\r
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\n" ); document.write( "\n" ); document.write( "        All you need to know are the parameters of the appropriate/relevant normal curve:
\n" ); document.write( "        its mean value and its standard deviation.\r
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\n" ); document.write( "\n" ); document.write( "        In your case,  the mean is  105410  dollars;  the standard deviation is  9680  dollars.\r
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\n" ); document.write( "\n" ); document.write( "        The probabilities they want from you, are the areas under this normal curve
\n" ); document.write( "        in the designed diapasons.\r
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\n" ); document.write( "\n" ); document.write( "        Now see how it works.\r
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document.write( "(a)  In part (a), they want you determine the area under the normal curve \r\n" );
document.write( "     between the raw mark of 90000 and 95000 dollars.\r\n" );
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document.write( "     In part (a), same as in other parts (b) and (c), the mean is 105410;  the standard deviation is 9680.\r\n" );
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document.write( "     You may use the standard function  \"normalcdf\"  in your calculator TI-83 or TI-84.\r\n" );
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document.write( "                         z1     z2    mean    SD     <<<---===  formatting pattern \r\n" );
document.write( "         P = normalcfd(90000, 95000, 105410, 9680)\r\n" );
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document.write( "     The calculator gives the answer  P = 0.0854,  or  8.54%.\r\n" );
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document.write( "(b)  In part (b), they want you determine the area under the normal curve \r\n" );
document.write( "     between the raw mark of 95000 and 11000 dollars  (very similar to part (a)).\r\n" );
document.write( "\r\n" );
document.write( "     In part (b), same as in other parts (a) and (c), the mean is 105410;  the standard deviation is 9680.\r\n" );
document.write( "\r\n" );
document.write( "     Again, you may use the standard function  \"normalcdf\"  in your calculator TI-83 or TI-84.\r\n" );
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document.write( "                         z1     z2    mean    SD     <<<---===  formatting pattern \r\n" );
document.write( "         P = normalcfd(95000, 110000, 105410, 9680)\r\n" );
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document.write( "     The calculator gives the answer  P = 0.5412,  or  54.12%.\r\n" );
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document.write( "(c)  In part (c), they want you determine the area under the normal curve \r\n" );
document.write( "     on the left of the raw mark of 80000 dollars.\r\n" );
document.write( "\r\n" );
document.write( "     In part (c), same as in other parts (a) and (b), the mean is 105410;  the standard deviation is 9680.\r\n" );
document.write( "\r\n" );
document.write( "     Again, you may use the standard function  \"normalcdf\"  in your calculator TI-83 or TI-84.\r\n" );
document.write( "\r\n" );
document.write( "                         z1     z2    mean    SD     <<<---===  formatting pattern \r\n" );
document.write( "         P = normalcfd(-9999, 80000, 105410, 9680)\r\n" );
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document.write( "     The calculator gives the answer  P = 0.0043,  or  0.43%.\r\n" );
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\n" ); document.write( "\n" ); document.write( "At this point, the problem is just solved.\r
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\n" ); document.write( "\n" ); document.write( "But I want present you an alternative way to solve this and similar problems.\r
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\n" ); document.write( "\n" ); document.write( "Go to website https://onlinestatbook.com/2/calculators/normal_dist.html
\n" ); document.write( "and use free of charge calculator there.\r
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\n" ); document.write( "\n" ); document.write( "It allows to do all these calculations, and every time it shows you
\n" ); document.write( "the area of interest under the normal curve.\r
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\n" ); document.write( "\n" ); document.write( "Its interface is very friendly, very simple and very convenient.\r
\n" ); document.write( "\n" ); document.write( "It will help you to learn the subject in 5 - 10 minutes.\r
\n" ); document.write( "\n" ); document.write( "You may play with this calculator as long as you need, until everything in the subject
\n" ); document.write( "becomes clear to you.\r
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\n" ); document.write( "\n" ); document.write( "After that, you may return to your regular hand calculator TI-83 / TI-84
\n" ); document.write( "enriched with full understanding of the subject.\r
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