<span>mean of 3.2 pounds and standard deviation of 0.8 pound</span>
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
Step-by-step explanation: To simplify, we will apply the <em>Quotient Rule</em>.
The 5's in this problem are bases so as you apply the quotient rule,
subtract the exponents but leave the base alone to get 5⁴.
We can also write 5⁴ as 5 · 5 · 5 · 5.
Answer step-by-step explanation:
We know that the critical t value for a 98% confidence level for a sample of size n = 18:
Finding degrees of freedom (n-1) = 17
-search the information in table t for 0.98 and find that t = 2.567