Answer:
1) 0.6% of the production is defective.
2) Ana will owe $570.
Explanation:
Both questions here are percentage problems
Percentage problems can be explained as a rule of three problem
In a rule of three problem, the first step is identifying the measures and how they are related, if their relationship is direct of inverse.
When the relationship between the measures is direct, as the value of one measure increases, the value of the other measure is going to increase too. In this case, the rule of three is a cross multiplication.
When the relationship between the measures is inverse, as the value of one measure increases, the value of the other measure will decrease. In this case, the rule of three is a line multiplication.
Percentage problems have a direct relationship between the measures.
1) The problem states that a quality control process finds 46.8 defects for every 7,800 units of production. And asks what percent of the production is defective? We have to answers how many defects are there for 100 units of production. So:
46.8 defects - 7,800 units
x defects - 100 units
7,800x = 4680
x = 0.6
0.6% of the production is defective.
2) The problem states that the medical insurance policy requires Ana to pay the first $100 of her hospital expense. The insurance company will then pay 90% of the remaining expense. The total bill is expected to be about $4,800.
Ana has to pay:
P = P1 + P2
-P1 :The first $100
-P2: 10% of the remaining expense. The remaining expense is $4,800-$100 = $4,700. Ana has to pay 10% of this. So
4700 - 100%
P2 - 10%
100P2 = 47000
P2 = $470
Ana will owe P = P1 + P2 = $100 + $470 = $570.