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Finding the Fourth Proportional to 656.30, 905.09 and 393.86

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Solution

The fourth proportional to 656.30, 905.09 and 393.86 is: 543.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.30 : 905.09 = 393.86 : x
  2. Step 2: Convert to fraction form
    656.30/905.09 = 393.86/x
  3. Step 3: Cross multiply
    656.30x = 905.09 × 393.86
  4. Step 4: Simplify right side
    656.30x = 356,472.25
  5. Step 5: Solve for x
    x = 356,472.25/656.30
  6. Step 6: Final answer
    x = 543.16

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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.