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Finding the Fourth Proportional to 728.60, 1,005.84 and 493.79

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Solution

The fourth proportional to 728.60, 1,005.84 and 493.79 is: 681.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.60 : 1,005.84 = 493.79 : x
  2. Step 2: Convert to fraction form
    728.60/1,005.84 = 493.79/x
  3. Step 3: Cross multiply
    728.60x = 1,005.84 × 493.79
  4. Step 4: Simplify right side
    728.60x = 496,668.11
  5. Step 5: Solve for x
    x = 496,668.11/728.60
  6. Step 6: Final answer
    x = 681.68

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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.