Answer:
120 liters of 60% alcohol solution is needed
Step-by-step explanation:
Let's assume
x liters of 60% alcohol solution is added
so, we get solution as


we are given
40 liters of a 20% alcohol solution is



so, total alcohol solution is

now, we can find total solutions
total solutions is

now, it is making 50% solution
so, we get

now, we can solve for x




So,
120 liters of 60% alcohol solution is needed
Answer:


Step-by-step explanation:
Area is found by mulitplying width and height.

in
The ratio is 0.5in : 1ft, so if you multiply that ratio to the answer, you should get the answer in feet.
in x


Answer:
I would have helped you but I just started learning about this
Answer:
The sample size must be atleast 3600
Step-by-step explanation:
We are given the following in the question:
The scores of individual students on the American College Testing (ACT) Program is a bell shaped distribution that is a normal distribution.
Population standard deviation = 6.0
We want that the sample standard deviation should not be more than 0.1.
Thus, the standard error should not be more than 0.1.
Standard error =

Putting values, we get,

Thus, the sample size must be atleast 3600