Answer:
Answers below
Step-by-step explanation:
a. Is x (approximately) a binomial random variable?
b. Give the probability distribution for x as a formula.
c. Find p(x = 2).
d. Find P(x <= 1).
x = quarts of 30% acid solution
y = quarts of 65% solution
x + y = 175
Each quart of the 30% solution contributes 0.30x quarts of acid; similarly, each quart of the 65% solution contributes 0.65y quarts of acid. So
0.3x + 0.65y = 0.55*175 = 96.25
That is, the chemist wants 175 quarts of a new mixture with a 55% concentration of acid, which comes out to 95.25 total quarts of acid. The total amounts of acid from either sides of this equation must balance out.
Now solve for x and y:
x + y = 175 ==> y = 175 - x
0.3x + 0.65y = 96.25 ==> 0.3x + 0.65(175 - x) = 96.25
==> 0.3x + 113.75 - 0.65x = 96.25
==> 17.5 = 0.35x
==> x = 50 ==> y = 125
Answer:
. .....
Step-by-step explanation:
It will take them 6 Pieces of wood rebuild it
Answer: 3 hours
Step-by-step explanation: we can make a variable for our answer(x)
Now, we need to find the speed of the boat without the current (y)
we can make this equation: d/t = s: 45/(y + 2.5) = 2 1/4
hence: y = 17.5
now we can substitute in the current's speed: y -2.5
17.5 - 2.5 is 15
now we can solve for x
45/15 = 3
hence, we get 3 hours as our answer