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Finding the Fourth Proportional to 686.87, 947.84 and 407.13

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Solution

The fourth proportional to 686.87, 947.84 and 407.13 is: 561.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.87 : 947.84 = 407.13 : x
  2. Step 2: Convert to fraction form
    686.87/947.84 = 407.13/x
  3. Step 3: Cross multiply
    686.87x = 947.84 × 407.13
  4. Step 4: Simplify right side
    686.87x = 385,894.10
  5. Step 5: Solve for x
    x = 385,894.10/686.87
  6. Step 6: Final answer
    x = 561.82

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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.