Answer: B) 4 BTUs/ft^3
Step-by-step:
For a cuboid of length L, width W and height H, the volume is:
V = L*W*H
In this case, we have:
L = 20ft
W = 15ft
H = 10ft
Then the volume of the room is:
V = 20ft*15ft*10ft = 3000 ft^3
Now we have 6 people, and each generate 400 BTUs per hour.
Then in total, they generate:
6*400 BTUs per hour
2400 BTUs per hour.
Now we want to find the BTUs per ft^3 produced in 5 hours.
Then if they generate 2400 BTUs per hour, in 5 hours they generate a total of:
5*2400 BTUs = 12000 BTUs
Now we take the quotient between the total BTUs and the volume of the room:
Q = (12000 BTUs)/(3000 ft^3) = 4 BTUs/ft^3
The correct option is B.
The z-score corresponding to a cumulative area of 1 - 0.0122 = 0.9878 is 2.25.
Therefore the z-score corresponding to a cumulative area of 0.0122 is the negative of 2.25 = -2.25.
There are two steps to this problem. The first step is to make an equation for the cost of each company. The cost of each one involves 2 variables. However, we can ignore the number of days since the question asks for per day.
CostA = 90 + .40(miles)
CostB = 30 + .70(miles)
We want to know when A is a better deal or when A costs less. That is when CostA < CostB. We can then substitute the right sides of our equations into the inequality. This will give:
90 + .40(miles) < 30 + .70(miles) This is where we will now begin to solve for the number of miles.
-30 -30 Subtract 30 from both sides.
60 + .4(miles) < .7(miles) Simplify
-.4(miles) -.4(miles) Subtract .4(miles) from both sides
60 < .3(miles) Simplify
/.3 /.3 Divide both sides by .3
200 < miles Simplify
So for A to cost less the number of miles must be greater than 200.
