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Finding the Fourth Proportional to 686.01, 946.71 and 391.28

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Solution

The fourth proportional to 686.01, 946.71 and 391.28 is: 539.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.01 : 946.71 = 391.28 : x
  2. Step 2: Convert to fraction form
    686.01/946.71 = 391.28/x
  3. Step 3: Cross multiply
    686.01x = 946.71 × 391.28
  4. Step 4: Simplify right side
    686.01x = 370,431.06
  5. Step 5: Solve for x
    x = 370,431.06/686.01
  6. Step 6: Final answer
    x = 539.98

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1.5x scale

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.