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Finding the Fourth Proportional to 687.60, 949.68 and 511.20

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Solution

The fourth proportional to 687.60, 949.68 and 511.20 is: 706.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.60 : 949.68 = 511.20 : x
  2. Step 2: Convert to fraction form
    687.60/949.68 = 511.20/x
  3. Step 3: Cross multiply
    687.60x = 949.68 × 511.20
  4. Step 4: Simplify right side
    687.60x = 485,476.42
  5. Step 5: Solve for x
    x = 485,476.42/687.60
  6. Step 6: Final answer
    x = 706.04

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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.