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Finding the Fourth Proportional to 656.91, 906.19 and 391.23

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Solution

The fourth proportional to 656.91, 906.19 and 391.23 is: 539.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.91 : 906.19 = 391.23 : x
  2. Step 2: Convert to fraction form
    656.91/906.19 = 391.23/x
  3. Step 3: Cross multiply
    656.91x = 906.19 × 391.23
  4. Step 4: Simplify right side
    656.91x = 354,527.74
  5. Step 5: Solve for x
    x = 354,527.74/656.91
  6. Step 6: Final answer
    x = 539.69

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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.