Can anybody help with this? Please!!
2 answers:
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Answer:
4 liters of 5% and 16 liters of 17.5%
Step-by-step explanation:
Let quantity of 5% be x liters and of 17.5% be y liters
x+y=20 hence y=20-x
Introducing percentages
0.05x+0.175(20-x)=0.15*20
0.05x+3.5-0.175x=3
-0.125x=-0.5
Therefore, y=20-x=20-4=16
You need 4 liters of 5% and 16 liters of 17.5% to achieve 20 liters of 15% acid solution
Answer:
324
Step-by-step explanation:
given that in a poll, 74% of the people polled answered yes to the question "Are you in favor of the death penalty for a person convicted of murder?"
i.e. Sample proportion
Margin of error = 4% = 0.04
Confidence level =90%
Z critical value for 90% = 1.645
Margin of error = 1.645 * std error
Hence std error =
Std error is also equal to
Sample size should be 324.
The formula is sample size = (Z critical value)^2 (pq)/(Margin of error )^2