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
Let p be the population proportion of parents who had children in grades K-12 were satisfied with the quality of education the students receive.
Given : Several years ago, 39% of parents who had children in grades K-12 were satisfied with the quality of education the students receive.
Set hypothesis to test :
Sample size : n= 1055
Sample proportion :
Critical value for 95% confidence :
Confidence interval :
Since , Confidence interval does not contain 0.39.
It means we reject the null hypothesis.
We conclude that 95% confidence interval represents evidence that parents' attitudes toward the quality of education have changed.