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Finding the Fourth Proportional to 656.60, 906.12 and 391.08

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Solution

The fourth proportional to 656.60, 906.12 and 391.08 is: 539.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.60 : 906.12 = 391.08 : x
  2. Step 2: Convert to fraction form
    656.60/906.12 = 391.08/x
  3. Step 3: Cross multiply
    656.60x = 906.12 × 391.08
  4. Step 4: Simplify right side
    656.60x = 354,365.41
  5. Step 5: Solve for x
    x = 354,365.41/656.60
  6. Step 6: Final answer
    x = 539.70

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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.