Answer:
Step-by-step explanation:
This is a differential equation problem most easily solved with an exponential decay equation of the form
. We know that the initial amount of salt in the tank is 28 pounds, so
C = 28. Now we just need to find k.
The concentration of salt changes as the pure water flows in and the salt water flows out. So the change in concentration, where y is the concentration of salt in the tank, is 
. Thus, the change in the concentration of salt is found in
inflow of salt - outflow of salt
Pure water, what is flowing into the tank, has no salt in it at all; and since we don't know how much salt is leaving (our unknown, basically), the outflow at 3 gal/min is 3 times the amount of salt leaving out of the 400 gallons of salt water at time t:
Therefore,
or just
and in terms of time,
Thus, our equation is
and filling in 16 for the number of minutes in t:
y = 24.834 pounds of salt
This cannot be fit into a normal distribution. While the first 7 runners all have times relatively close, the time of the last runner is an outlier, as it is too far from the other data points. The standard deviation is calculated by taking the mean, subtracting each value from the mean, squaring the deviations, adding these, then dividing by the number of data points (7), and taking the square root. This gives an answer of SD = 0.1107.
36 goodie bags can be created in total because there are only 36 posters.
Answer:
Urban, 2.1 mins
Step-by-step explanation:
36 ÷ 3 = 2 (Gorge's)
42 ÷ 2 = 2.1 (Urban)
The answer is 50000+600+70+9
