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Finding the Fourth Proportional to 655.79, 905.04 and 393.89

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Solution

The fourth proportional to 655.79, 905.04 and 393.89 is: 543.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    655.79 : 905.04 = 393.89 : x
  2. Step 2: Convert to fraction form
    655.79/905.04 = 393.89/x
  3. Step 3: Cross multiply
    655.79x = 905.04 × 393.89
  4. Step 4: Simplify right side
    655.79x = 356,481.68
  5. Step 5: Solve for x
    x = 356,481.68/655.79
  6. Step 6: Final answer
    x = 543.60

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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.