Home / 815-2,120

Finding the Third Proportional to 815 and 2,120

Calculator

Solution

The third proportional to 815 and 2,120 is: 5,514.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    815 : 2,120 = 2,120 : x
  2. Step 2: Convert to fraction form
    815/2,120 = 2,120/x
  3. Step 3: Cross multiply
    815x = 2,120 × 2,120
  4. Step 4: Simplify right side
    815x = 4,494,400
  5. Step 5: Solve for x
    x = 4,494,400/815
  6. Step 6: Final answer
    x = 5,514.60

Related Problems

Find third proportional to 407.50 and 1,060
Half scale
Find third proportional to 1,630 and 4,240
Double scale
Find third proportional to 817 and 2,125
Similar ratio
Find third proportional to 1,222.50 and 3,180
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.60) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.