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Finding the Fourth Proportional to 686.97, 947.96 and 407.18

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Solution

The fourth proportional to 686.97, 947.96 and 407.18 is: 561.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.97 : 947.96 = 407.18 : x
  2. Step 2: Convert to fraction form
    686.97/947.96 = 407.18/x
  3. Step 3: Cross multiply
    686.97x = 947.96 × 407.18
  4. Step 4: Simplify right side
    686.97x = 385,990.35
  5. Step 5: Solve for x
    x = 385,990.35/686.97
  6. Step 6: Final answer
    x = 561.87

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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.