activity 5-b-1 (the magic of proportions) 1.) party planning 2.) birthday gift
TRANSCRIPT
Activity 5-B-1 (The Magic of Proportions)
1.) Party Planning2.) Birthday Gift
chickenofpounds 3people8
On July 4th Kevin wants to have a big family get together. He finds an advertisement in the newspaper that had chicken on sale for $11.50 for 3 pounds. Kevin knows that 3 pounds of chicken will feed 8 people. Before going to the store, he wants to find out how many pounds of chicken he needs to buy to feed 30 people.
Party Planning:
Since 3 pounds of chicken will feed 8 people he sets up a ratio of people to number of pounds of chicken.
Kevin knows that he can find the number of pounds of chicken needed by setting up a proportion. He knows that the numerator in each ratio will represent the number of people and the denominator will represent the number of pounds of chicken. To solve this problem Kevin sets the ratios equivalent to form a proportion…Then solves the proportion using cross products…
38peopl
elbs. chicken
x30
=x8303
8x9088
11.25 = xThe number of pounds of
chicken needed is 11.25 pounds
The Birthday Gift:
Kevin is going shopping for a pair of diamond earrings for his wife’s birthday. The only problem is he needs to spend less than $450 on his gift because he made a promise to his wife that he would not spend more. While browsing at Zale’s he found the perfect pair of ¼ karat diamond earrings on sale. The original cost of the earrings was $475, they are now on sale for 20% of the original price.
Kevin knows that percentages are parts of a whole. So 20% is equivalent to the ratio…
Kevin knows that he can find the discount by setting up a proportion. He knows that the numerator in each ratio will represent the savings or discount and the denominator will represent the total.
To solve this problem Kevin sets the ratios equivalent to form a proportion…
Then solves the proportion using cross products…
100
20%20 discountxwhere
x
475$
100
20
475
x x 10020475
x1009500100
100
$95 = x
To find the sale price the discount will need to be subtracted from the original price…$475 – 95 = $380