Home / 715-820

Finding the Third Proportional to 715 and 820

Calculator

Solution

The third proportional to 715 and 820 is: 940.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    715 : 820 = 820 : x
  2. Step 2: Convert to fraction form
    715/820 = 820/x
  3. Step 3: Cross multiply
    715x = 820 × 820
  4. Step 4: Simplify right side
    715x = 672,400
  5. Step 5: Solve for x
    x = 672,400/715
  6. Step 6: Final answer
    x = 940.42

Related Problems

Find third proportional to 357.50 and 410
Half scale
Find third proportional to 1,430 and 1,640
Double scale
Find third proportional to 717 and 822
Similar ratio
Find third proportional to 1,072.50 and 1,230
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.15) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.