12 3/8 ÷ 3/4
change the mixed fraction to improper....
99 3
__ ÷ __
8 4
now change the sign to a multiplication sign and flip 3/4.
99 4 396
__× __= _____
8 3 24
396/24..... that changes to 16 22/24. Simplify it and it will be 16 11/12.
999946
----------
10,000,000
The quantity you want is the area under the standard normal curve (with mean 100 and std dev 15) between 110 and 120.
According to my TI-83 calculator,
normalcdf(110,120, 100, 15) = 0.16, or 16%.
A = LW......W = A/L
A = 5/8
L = 10
W = (5/8) / 10
W = 5/8 * 1/10
W = 5/80 = 1/16
