Answer:
The proportion of students whose height are lower than Darnell's height is 71.57%
Step-by-step explanation:
The complete question is:
A set of middle school student heights are normally distributed with a mean of 150 centimeters and a standard deviation of 20 centimeters. Darnel is a middle school student with a height of 161.4cm.
What proportion of proportion of students height are lower than Darnell's height.
Answer:
We first calculate the z-score corresponding to Darnell's height using:

We substitute x=161.4 ,
, and
to get:

From the normal distribution table, we read 0.5 under 7.
The corresponding area is 0.7157
Therefore the proportion of students whose height are lower than Darnell's height is 71.57%
To solve this problem, we will subtract the volume of the cylinder from the volume of the rectangular prism.
The volume of a cylinder is: pi*r^2*h
Substitute 2 in for r and 6 in for h. If the diameter is 4, then the radius is 2.
pi*2^2*6
pi*4*6
pi*24
=75.4 ft^2
The volume of the rectangular prism is: l*w*h.
Substitute 6 in for l, w and h, since all edges are equal.
6*6*6
36*6
=216 ft^2
Subtract 75.4 from 216
216-75.4=140.6
There is 140.6 cubic feet of concrete left in the block.
Answer should be 2, 7/2 hopefully this helped ^^