Answer:
B. 236.3
Step-by-step explanation:
Population density can be found by dividing the number of people by the area of the land.
number of people / land area
The population is 20,510 people and the area is 86.8 square miles.
20,510 people / 86.8 square miles
Divide 20,510 by 86.8
236.290323 people /square mile
Round to the nearest tenth. The 9 in the hundredth place tell us to round the 2 to a 3 in the tenth place.
236.3 people/ square mile
There are 236.3 people per square mile and B is correct.
Answer:
Step-by-step explanation:
Given Data,
Q=23000 J
c=4.184 J/g °c
Δt= 68 °c
m=?
By using this equation,
Q=mcΔt
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 .
Answer:
Where ??
Step-by-step explanation:
