Section 2

Explore

 

In Discover you may have noticed there are different ways of setting up a proportion to arrive at the same answer. Using a table to set up a proportion instead of ratios is a strategy that can be helpful.

 

Try This 2

 

You can purchase a 5-lb bag of peanuts at the store for $2.10.

1. Assuming that the price per pound doesn't change, how much will a 7-lb bag of peanuts cost?
   
   
   1. Use the table to set up a proportion and solve the question.
      
      

      	Cost	Pounds
      First Bag	$2.10	5
      Second Bag	x	7

      
      
   2. Create two ratios based on this problem. Use these ratios to set up a different proportion and solve the question.
      
      
2. What is the cost of peanuts per pound?

Self-Check 1

1. The temperature dropped 15°C in the last 30 days. If the rate of temperature drop remains the same, how many degrees will the temperature drop in the next 10 days?
   
   

   	Temperature Drop (°C)	Number of Days
   Initial Drop	15	30
   New Drop	x	10

   
   Answer
   
   
2. Graph the points from question 1 with number of days on the horizontal axis. Join the points and find the slope of the resulting line. What does the slope tell you about the temperature drop? Answer