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Finding the Fourth Proportional to 656.30, 905.85 and 394.31

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Solution

The fourth proportional to 656.30, 905.85 and 394.31 is: 544.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.30 : 905.85 = 394.31 : x
  2. Step 2: Convert to fraction form
    656.30/905.85 = 394.31/x
  3. Step 3: Cross multiply
    656.30x = 905.85 × 394.31
  4. Step 4: Simplify right side
    656.30x = 357,187.98
  5. Step 5: Solve for x
    x = 357,187.98/656.30
  6. Step 6: Final answer
    x = 544.24

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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.