Home / 209.80-314.70-81.55

Finding the Fourth Proportional to 209.80, 314.70 and 81.55

Calculator

Solution

The fourth proportional to 209.80, 314.70 and 81.55 is: 122.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.80 : 314.70 = 81.55 : x
  2. Step 2: Convert to fraction form
    209.80/314.70 = 81.55/x
  3. Step 3: Cross multiply
    209.80x = 314.70 × 81.55
  4. Step 4: Simplify right side
    209.80x = 25,662.59
  5. Step 5: Solve for x
    x = 25,662.59/209.80
  6. Step 6: Final answer
    x = 122.32

Related Problems

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.