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Finding the Fourth Proportional to 498, 687.20 and 288.12

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Solution

The fourth proportional to 498, 687.20 and 288.12 is: 397.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    498 : 687.20 = 288.12 : x
  2. Step 2: Convert to fraction form
    498/687.20 = 288.12/x
  3. Step 3: Cross multiply
    498x = 687.20 × 288.12
  4. Step 4: Simplify right side
    498x = 197,996.06
  5. Step 5: Solve for x
    x = 197,996.06/498
  6. Step 6: Final answer
    x = 397.58

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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.