Answer:
D. 216 cubic centimetres.
Step-by-step explanation:
The answer is D, because 6 to the 3rd power is 216. therefore, if the side length is 6, the answer is 216.
The answer is A because the same rule applies
Answer:
- Circumference = 69.14cm
- Area = 380.29cm²
Step-by-step explanation:
Circumference.
Circumference of a circle is calculated by the formula:
= Pie * diameter
= π * diameter
= 22/7 * 22
= 69.14 cm
Area
Area of circle:
= Pie * radius ²
Radius = diameter/2
= 22/2
= 11 cm
Area = 22/7 * 11²
= 22/7 * 121
= 380.29 cm²
Let Xi be the random variable representing the number of units the first worker produces in day i.
Define X = X1 + X2 + X3 + X4 + X5 as the random variable representing the number of units the
first worker produces during the entire week. It is easy to prove that X is normally distributed with mean µx = 5·75 = 375 and standard deviation σx = 20√5.
Similarly, define random variables Y1, Y2,...,Y5 representing the number of units produces by
the second worker during each of the five days and define Y = Y1 + Y2 + Y3 + Y4 + Y5. Again, Y is normally distributed with mean µy = 5·65 = 325 and standard deviation σy = 25√5. Of course, we assume that X and Y are independent. The problem asks for P(X > Y ) or in other words for P(X −Y > 0). It is a quite surprising fact that the random variable U = X−Y , the difference between X and Y , is also normally distributed with mean µU = µx−µy = 375−325 = 50 and standard deviation σU, where σ2 U = σ2 x+σ2 y = 400·5+625·5 = 1025·5 = 5125. It follows that σU = √5125. A reference to the above fact can be found online at http://mathworld.wolfram.com/NormalDifferenceDistribution.html.
Now everything reduces to finding P(U > 0) P(U > 0) = P(U −50 √5125 > − 50 √5125)≈ P(Z > −0.69843) ≈ 0.757546 .
There are 27 bricks in the 12th row. Hope this helps ! :)
