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Question 153099This question is from textbook
: Hello, Im would appricate an help that you can offer me. Im working on rate, unit and proportions. I have read through my chapter and still a little puzzled.
1. a diver descends 10 ft in 16 sec. What is the rate of descent in feet per second?
2. An 18-oz jar of blackberry jam is on sale for $4.50. find the unit price in dollars per ounce.
3. Determine whether the pairs 10,8 and 38, 26 are proportional.
I think i can figure out the problems but im not sure how i would show the work. Please help. thank you Cheryl
This question is from textbook
Answer by nerdybill(7384)   (Show Source):
You can put this solution on YOUR website! 1. a diver descends 10 ft in 16 sec. What is the rate of descent in feet per second?
If a "diver descends 10 ft in 16 sec" the rate is:
10 ft per 16 secs
as a "ratio" it would be:
10 ft/16 secs
if we want it, in terms of "per second", we simply divide 10 by 16 to get:
0.625 ft/1 sec
or, we could eliminate the '1' and rewrite it as:
0.625 ft/sec
.
2. An 18-oz jar of blackberry jam is on sale for $4.50. find the unit price in dollars per ounce.
If "An 18-oz jar of blackberry jam is on sale for $4.50" the cost is:
$4.50 per 18 ozs
as a "ratio" it would be:
4.50 dollars:18 ozs
or
4.50 dollars/18 ozs
if we want it, in terms of "per ounce", we simply divide 4.50 by 18 to get:
0.25 dollars/1 oz
or, we could eliminate the '1' and rewrite it as:
0.25 dollars/oz
.
3. Determine whether the pairs 10,8 and 38, 26 are proportional.
For any proportion say:
a/b = c/d
'b' and 'c' are called the "means"
and
'a' and 'd' are called the "extremes"
if two ratios are proportional then:
bc = ad
.
For your pairs, 10,8 and 38,26, we could write each ratio as:
10:8 and 38:26
If they were proportional, then we could set each ratio equal to each other:
10:8 = 38:26
or
10/8 = 38/26
to check whether they are proportional, multiply means and extremes:
10*26 = 8*38
260 = 304
Since they are NOT equal -- the ratios are NOT proportional.
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