Answer:
About twenty-one percent of twelve month old boys are shorter than 28.8 inches.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
About twenty-one percent of twelve month old boys are shorter than what height?
This is the value of X when Z has a pvalue of 0.21. So it is X when Z = -0.805.
About twenty-one percent of twelve month old boys are shorter than 28.8 inches.
Yearly salary would be 240,000 for 5,000 and 48,000 for 1,000 a week
The volume of the cube is base times width times height, or any of these measurements cubed, since they're all the same.
Therefore, the volume of the cube is:
12³ = 1728 in³
The volume of the cylinder is π*r²*h, where r is the radius and h is height
Remember that the diameter is twice the radius, so the radius is 2 in and the height is 5 in.
Therefore, each can has a volume of π * 2² * 5 = 20π
Approximating π as 3.14....
The volume of each can is 62.8 in³
1728 ÷ 62.8 = 27.5
Rounding down, 27 cans can fit in the crate.
This is how I suspect the teach wanted you to solve, since it involves finding the volume of both shapes and using pi. However, this is not actually how many cans can fit, because it does not take into account the fact that not every inch of available space will be used.
Here is another way to solve,taking this fact into account, that gives the more accurate answer:
Each can has a diameter of 4in, which means that they each require a square of 4 x 4 in to accommodate their base.
The base of each can requires 16 in² of space in the crate.
The base of the cube is 12 x 12, so the area of the base is 144 in²
144 ÷ 16 = 9, so the base of the cube, or bottom of the box, can fit 9 cans, arranged 3 by 3.
The cube has a height of 12 inches, and each can is 5 inches tall. Therefore, two of these stacks can fit in the box, for 9 x 2 = 18 cans.
This is a much better answer, as it takes into account the fact that the cans can't occupy every inch of available space in the cube.
Answer:
1.78 feet.
Step-by-step explanation:
If they cost $20 each and its $2 per square foot, the area of the spheres
is 20 / 2 = 10 ft^2.
Area of sphere = 4 π r^2 = 10 (where r = the radius)
---> r^2 = 10 / 4π
= 0.796
---> r = 0.892 ft
So the diameter = 2 * r
= 1.78 feet to nearest hundredth.
