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Finding the Fourth Proportional to 728.61, 1,005.30 and 429.87

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Solution

The fourth proportional to 728.61, 1,005.30 and 429.87 is: 593.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.61 : 1,005.30 = 429.87 : x
  2. Step 2: Convert to fraction form
    728.61/1,005.30 = 429.87/x
  3. Step 3: Cross multiply
    728.61x = 1,005.30 × 429.87
  4. Step 4: Simplify right side
    728.61x = 432,148.31
  5. Step 5: Solve for x
    x = 432,148.31/728.61
  6. Step 6: Final answer
    x = 593.11

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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.