Question 923568
mean = $2, sd = $0.50
A. Empirical rule: one  standard deviation from the mean accounts for about 68% of the set 
.......
b. P( $4 < x < $5) = normalcdf(4,5,2,.50)  = .00003  0r .003%
.......
C. P( $1.50 < x < $3.50) 
{{{z =blue (x - mu)/blue(sigma/sqrt(n))}}}
z =  -.50/(.50 = -1  and z = 1.50/.50 = 3
 P( $1.50 < x < $3.50) = normalcdf(-1, 3) = .84  0r 84%
0r
 P( $1.50 < x < $3.50) = P(z &#8804; 3) - P( z &#8804; - 1) = .9987 - .1587 = .84  0r 84%