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Finding the Fourth Proportional to 686.16, 946.88 and 391.44

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Solution

The fourth proportional to 686.16, 946.88 and 391.44 is: 540.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.16 : 946.88 = 391.44 : x
  2. Step 2: Convert to fraction form
    686.16/946.88 = 391.44/x
  3. Step 3: Cross multiply
    686.16x = 946.88 × 391.44
  4. Step 4: Simplify right side
    686.16x = 370,646.71
  5. Step 5: Solve for x
    x = 370,646.71/686.16
  6. Step 6: Final answer
    x = 540.18

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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.