Answer:
Step-by-step explanation:
Given that the height in inches, of a randomly chosen American woman is a normal random variable with mean μ = 64 and variance 2 = 7.84.
X is N(64, 2.8)
Or Z = 
a) the probability that the height of a randomly chosen woman is between 59.8 and 68.2 inches.

b) 
c) For 4 women to be height 260 inches is equivalent to
4x will be normal with mean (64*4) and std dev (2.8*4)
4x is N(266, 11.2)

d) Z is N(0,1)
E(Z19) = 
since normal distribution is maximum only between 3 std deviations form the mean on either side.
See attachment for one such shell. The volume is given by the sum of infinitely many thin shells like this, each with radius

and height determined by the vertical distance between the upper blue curve and the lower orange curve for any given

, i.e.

.
The volume is then
Answer:
3003 units^3.
Step-by-step explanation:
Just multiply the dimensions :
11 * 13 * 21
= 143 * 21
= 3003 units^3.
In the 7th and 8th grade combined, there 3+5 girls = 8 girls, and 7+5 boys = 12 boys. If there are only boys and girls, then there are 12+8=20 students in all.
The fraction of girls out of the total is P = 8/20 = 2/5.