Answer:
what statement?
Step-by-step explanation:
<h3>
Answer: 4/5</h3>
Explanation:
We have 24 adults who passed and 16 teens who passed. So 24+16 = 40 people passed total.
There are 24+8+16+2 = 50 people total
If you pick someone at random, the probability of them passing is 40/50 = 4/5.
In decimal form, this is 4/5 = 0.80 which converts to 80%
Suppose you add x liters of pure water to the 10 L of 25% acid solution. The new solution's volume is x + 10 L. Each L of pure water contributes no acid, while the starting solution contains 2.5 L of acid. So in the new solution, you end up with a concentration of (2.5 L)/(x + 10 L), and you want this concentration to be 10%. So we have

and so you would need to add 15 L of pure water to get the desired concentration of acid.
Answer:
d 60 ft 2
Step-by-step explanation:
Answer:
Pr(X >42) = Pr( Z > -2.344)
= Pr( Z< 2.344) = 0.9905
Step-by-step explanation:
The scenario presented can be modeled by a binomial model;
The probability of success is, p = 0.65
There are n = 80 independent trials
Let X denote the number of drivers that wear a seat belt, then we are to find the probability that X is greater than 42;
Pr(X > 42)
In this case we can use the normal approximation to the binomial model;
mu = n*p = 80(0.65) = 52
sigma^2 = n*p*(1-p) = 18.2
Pr(X >42) = Pr( Z > -2.344)
= Pr( Z< 2.344) = 0.9905