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Finding the Fourth Proportional to 419.20, 578.69 and 279.55

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Solution

The fourth proportional to 419.20, 578.69 and 279.55 is: 385.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.20 : 578.69 = 279.55 : x
  2. Step 2: Convert to fraction form
    419.20/578.69 = 279.55/x
  3. Step 3: Cross multiply
    419.20x = 578.69 × 279.55
  4. Step 4: Simplify right side
    419.20x = 161,769.20
  5. Step 5: Solve for x
    x = 161,769.20/419.20
  6. Step 6: Final answer
    x = 385.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.