<PRE><B>Question 80681</B>
In the question u is for population mean and o is for Population standards deviation thank you .

Let X  be a normally distributed random variable with u=100  and o=15			The probability that   is between 80 and 120 is (to the 			nearest whole percent)
	a.  8 % 	b.   82 %	c.  91% 	d. answer not listed
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If you have a Ti calulator use normalcdf(80,120,100,15) = 0.8175...
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If you do not find the z-scores of 80 and of 120:
z(80)=(80-100)/15 = -1.333333
z(120)=(120-100)/15 = 1.333333
Probability you want is normalcdf(-1.33333,1,33333)=0.8175...
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Cheers,
Stan H. </PRE>