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Finding the Fourth Proportional to 656.90, 906.62 and 391.35

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Solution

The fourth proportional to 656.90, 906.62 and 391.35 is: 540.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.90 : 906.62 = 391.35 : x
  2. Step 2: Convert to fraction form
    656.90/906.62 = 391.35/x
  3. Step 3: Cross multiply
    656.90x = 906.62 × 391.35
  4. Step 4: Simplify right side
    656.90x = 354,805.74
  5. Step 5: Solve for x
    x = 354,805.74/656.90
  6. Step 6: Final answer
    x = 540.12

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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.