Answer:
-3
the blue dot on the no line represent -3
<span>Dr. Graham currently has two acid solutions.
60% acid AND 20% acid </span>
Dr. Graham needs 30 L of a 50% acid solution
We set up 2 equations in which s = 60% acid and t = 20% acid
A) s + t = 30
B) .60s + .20t = (.50 * 30)
We multiply equation A by -.20
A) = -.20s -.20t = -6 then we add it to B)
B) .60s + .20t = 15
.40s = 9
s = 22.5
t = 7.5
So, she needs to mix 22.5 liters of 60% acid with 7.5 liters of 20% acid.
Source:
http://1728.org/mixture.htm
Answer:
1.2
Step-by-step explanation:
The variance of a binomial distribution is:
σ² = n p (1 − p)
where n is the number of trials and p is the probability of success.
Given n = 5 and p = 0.40:
σ² = 5 (0.40) (1 − 0.40)
σ² = 1.2
Answer:
128.69.
Step-by-step explanation:
The variance is np(1 - p)
= 625*(0.28) * 0.71
= 128.69.
