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Finding the Fourth Proportional to 212.04, 318.12 and 139.80

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Solution

The fourth proportional to 212.04, 318.12 and 139.80 is: 209.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.04 : 318.12 = 139.80 : x
  2. Step 2: Convert to fraction form
    212.04/318.12 = 139.80/x
  3. Step 3: Cross multiply
    212.04x = 318.12 × 139.80
  4. Step 4: Simplify right side
    212.04x = 44,473.18
  5. Step 5: Solve for x
    x = 44,473.18/212.04
  6. Step 6: Final answer
    x = 209.74

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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.