Answer:
95% confidence interval: (0.325 ,0.383)
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 231
Sample mean = 0.354 ppm
Sample standard deviation = 0.231 ppm
95% confidence interval:
Putting the values, we get,
Answer:
8/3
Step-by-step explanation:
i put equations as this:
x+40 = y
where x is galllons of pure mixture and y is the gallons of the new mixture
the other equation i id was:
x+0.2(40) = 0.25y
x+8 = 0.25y
y = 4x+32
solve using substitution
(x+40) = 4x+32
x = 4x-8
-3x = -8
x = 8/3
