The weights of 12-year old boys are normally distributed with a mean of 89 lbs. If 68% of 12 year old boys are between the weights of 82.7 lbs and 95.3 lbs, what is the standard deviation? A
34
B
6.3
C
3.5
D
12.6

hope it you

step-by-step explanation:

sin(7pi/6 - pi/3)  

= sin(7pi/6 - 2pi/6)  

= sin(5pi/6)  

= sin(pi - pi/6)  

= sin(pi/6)  

= 1/2  

sin 7pi/6 - sin pi/3  

= sin (pi + pi/6) - sin pi/3  

= -sin pi/6 - sin pi/3  

= -1/2 - sqrt(3)/2  

= -(1+sqrt(3))2