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Finding the Fourth Proportional to 728.50, 1,005.18 and 429.80

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Solution

The fourth proportional to 728.50, 1,005.18 and 429.80 is: 593.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.50 : 1,005.18 = 429.80 : x
  2. Step 2: Convert to fraction form
    728.50/1,005.18 = 429.80/x
  3. Step 3: Cross multiply
    728.50x = 1,005.18 × 429.80
  4. Step 4: Simplify right side
    728.50x = 432,026.36
  5. Step 5: Solve for x
    x = 432,026.36/728.50
  6. Step 6: Final answer
    x = 593.04

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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.