document.write( "Question 766645: The following sample observations were randomly selected.
\n" ); document.write( "X: 4,5,3,6,10
\n" ); document.write( "Y: 4,6,5,7,7
\n" ); document.write( "a. Determine the regression equation.
\n" ); document.write( "b. Determine the value of Ŷ when X is 7.
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Algebra.Com's Answer #467105 by MathLover1(20850)\"\" \"About 
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The regression equation minimizes the square of the difference between the \"y\" values of the sample points and a line of the form \"y=a%2Ax%2Bb\". Carrying out the math, this gives\r
\n" ); document.write( "\n" ); document.write( "\"a+=+%28N%2ASxy-Sx%2ASy%29%2FD\"
\n" ); document.write( "\"b+=+%28Sy%2ASxx-Sx%2ASxy%29%2FD\"\r
\n" ); document.write( "\n" ); document.write( "where\r
\n" ); document.write( "\n" ); document.write( "\"D=N%2ASxx-Sx%2ASx\"\r
\n" ); document.write( "\n" ); document.write( "and
\n" ); document.write( "\"N\"=number of samples,
\n" ); document.write( "\"Sx+\"= sum of \"x\",
\n" ); document.write( "\"Sy\"=sum of \"y\",
\n" ); document.write( "\"Sxx\"=sum of \"x%5E2\",
\n" ); document.write( "\"Sxy\"=sum of \"x%2Ay\"\r
\n" ); document.write( "\n" ); document.write( "This gives\r
\n" ); document.write( "\n" ); document.write( "\"a=53%2F146=0.363\"
\n" ); document.write( "\"b=275%2F73=3.767\"\r
\n" ); document.write( "\n" ); document.write( "The value for \"y\" when \"x=7\" is \"7a%2Bb+=+921%2F146+=+6.308\"\r
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