document.write( "Question 885649: The amount of snowfall falling in a certain mountain range is normally distributed with a mean of 70 inches, and a standard deviation of 10 inches. What is the probability that the mean annual snowfall during 25 randomly picked years will exceed 72.8 inches? \n" ); document.write( "
Algebra.Com's Answer #535319 by Theo(13342)\"\" \"About 
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pm = population mean
\n" ); document.write( "psd = population standard deviation
\n" ); document.write( "n = sample size
\n" ); document.write( "se = standard error = standard deviation of the distribution of sample means
\n" ); document.write( "xm = sample mean\r
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\n" ); document.write( "\n" ); document.write( "in this problem:
\n" ); document.write( "pm = 70
\n" ); document.write( "sm = 72.8
\n" ); document.write( "n = 25
\n" ); document.write( "psd = 10
\n" ); document.write( "se = psd / sqrt(n) = 10 / sqrt(25) = 10 / 5 = 2\r
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\n" ); document.write( "\n" ); document.write( "z = (sm - pm) / se = (72.8 - 70) / 2 = 2.8 / 2 = 1.4\r
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\n" ); document.write( "\n" ); document.write( "z factor of 1.4 gives you an area to the left of it of .9192 which means the area to the right of it is equal to 1 - .9192 = .0808.\r
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\n" ); document.write( "\n" ); document.write( "since you want to know the probability that the z score is greater than 1.4, then you want the area to the right of it.\r
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\n" ); document.write( "\n" ); document.write( "your answer is .0808.\r
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