document.write( "Question 1183700: Let us assume that from a population with mean μ=100 and standard
\n" ); document.write( "deviation σ=15 a sample random variable of n=900 is selected.
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\n" ); document.write( " What is the probability P(X ≤ 101.1)? \r
\n" ); document.write( "\n" ); document.write( " What is the probability P(X ≥ 101.5)? \r
\n" ); document.write( "\n" ); document.write( " What is the probability P(99.3 < X ≤ 100.5)? \r
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Algebra.Com's Answer #814159 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
For normal distributions, consider < and ≤ the same. Also consider > and ≥\r\n" );
document.write( "the same.

\n" ); document.write( " Let us assume that from a population with mean μ=100 and standard
\n" ); document.write( "deviation σ=15 a sample random variable of n=900 is selected.
\n" ); document.write( "
\n" ); document.write( " What is the probability P(X ≤ 101.1)?
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\r\n" );
document.write( "On your TI-84, \r\n" );
document.write( "press 2ND \r\n" );
document.write( "press VARS\r\n" );
document.write( "press 2\r\n" );
document.write( "\r\n" );
document.write( "Make the screen read: \r\n" );
document.write( "\r\n" );
document.write( "    normalcdf\r\n" );
document.write( "lower:-9999999\r\n" );
document.write( "upper:101.1\r\n" );
document.write( "μ:100\r\n" );
document.write( "σ:15/√(900)        <---the square root key is 2ND x2\r\n" );
document.write( "Paste\r\n" );
document.write( "\r\n" );
document.write( "Scroll down with the down arrow to Paste\r\n" );
document.write( "\r\n" );
document.write( "Read on the screen\r\n" );
document.write( "\r\n" );
document.write( "normalcdf(-9999999,101.1,100,15/√(900))\r\n" );
document.write( "\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "\r\n" );
document.write( "Read 0.9860966011, round to 0.9861\r\n" );
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document.write( "
What is the probability P(X ≥ 101.5)?
 \r\n" );
document.write( "\r\n" );
document.write( "As above but make the screen read\r\n" );
document.write( "\r\n" );
document.write( "    normalcdf\r\n" );
document.write( "lower:101.5\r\n" );
document.write( "upper:99999999\r\n" );
document.write( "μ:100\r\n" );
document.write( "σ:15/√(900)     \r\n" );
document.write( "Paste\r\n" );
document.write( "\r\n" );
document.write( "Answer:  0.0013499672, round to 0.0013\r\n" );
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document.write( "
What is the probability P(99.3 < X ≤ 100.5)?
 \r\n" );
document.write( "\r\n" );
document.write( "As above but make the screen read\r\n" );
document.write( "\r\n" );
document.write( "    normalcdf\r\n" );
document.write( "lower:99.3\r\n" );
document.write( "upper:100.5\r\n" );
document.write( "μ:100\r\n" );
document.write( "σ:15/√(900)    \r\n" );
document.write( "Paste\r\n" );
document.write( "\r\n" );
document.write( "Answer:  0.7605880293, round to 0.7606\r\n" );
document.write( "\r\n" );
document.write( "Edwin

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