the probability that if you pick only one, it's defective, is 250/6700
Therefore, the probability that one is not defective is 6450/6700
a. You want all 4 to not be defective: (6450/6700)^4
b. all 100 have to be not defective: (6450/6700)^100
If you type this into a calculator, you will get about 0.022, so a probability of 2 % that all of them are not defective. As this is a very small probability, the outlet should plan with returned tires.
For this case we have an equation of the form:
f (w) = A * (b) ^ w
Where,
A: initial amount
b: growth rate
w: number of weeks
Substituting values we have:
f (w) = 400 * (1.05) ^ w
Answer:
the beetle population can be determined after a number of weeks, w, with the following function:
f (w) = 400 * (1.05) ^ w
185 • 12 = $2,220
So your answer is $2,220
Peter's account is 910-40x, and Marla's account is 470-2x. This is a system, so you must find the number that makes both equations end up with the same number. Basically trial and error. Here is what I did:
Let's try the number 10. 910-400=510 and 470-20=450. I need a higher number.
Let's try 13 next. 910-520=390 and 470-26=444. Now the number has to be lower.
Let's try 12. 910-480=430 and 470-24=446. Close, and a little lower.
11.5 is too low, and 11.7 is too high. 11.6 has Equation 1 at 446 and Equation 2 at 446.8. Very close!
It is somewhere around 11.6. I hope that this can give you a start in figuring it out, because I don't believe in giving the complete answer, because then you do not learn anything from it.
