C = 2πr
c/2π = 2πr/2π <--divide both sides by 2π
c/2π = r
r = c/2π <-- answer :)
We rewrite the equation:
y = y0 * e ^ (- 0.0002 * t)
In this equation:
I = represents the initial amount of the isotope
We have then:
89% of the isotope left:
0.89 * y0 = y0 * e ^ (- 0.0002 * t)
We clear the time:
e ^ (- 0.0002 * t) = 0.89
Ln (e ^ (- 0.0002 * t)) = Ln (0.89)
-0.0002 * t = Ln (0.89)
t = Ln (0.89) / (- 0.0002)
t = 582.6690813
round to the nearest year:
t = 583 years
Answer:
There will be 89% of the isotope left in about:
t = 583 years
Using the binomial distribution, it is found that the probability that exactly 36 of them buy a product is of 0.044.
For each first-time visitor, there are only two possible outcomes, either they buy a product, or they do not. The probability of a first-time visitor buying a product is independent of any other first-time visitor, hence the binomial distribution is used to solve this question.
<h3>What is the binomial distribution formula?</h3>
The formula is:


The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem:
- 45% of first-time visitors to its website do not buy any of its products, hence 55% buy, that is, p = 0.55.
- There are 75 first-time visitors on a given day, hence n = 75.
The probability that exactly 36 of them buy a product is P(X = 36), hence:


More can be learned about the binomial distribution at brainly.com/question/24863377