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Finding the Fourth Proportional to 1,209.87, 1,815.07 and 429.92

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Solution

The fourth proportional to 1,209.87, 1,815.07 and 429.92 is: 644.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.87 : 1,815.07 = 429.92 : x
  2. Step 2: Convert to fraction form
    1,209.87/1,815.07 = 429.92/x
  3. Step 3: Cross multiply
    1,209.87x = 1,815.07 × 429.92
  4. Step 4: Simplify right side
    1,209.87x = 780,324.74
  5. Step 5: Solve for x
    x = 780,324.74/1,209.87
  6. Step 6: Final answer
    x = 644.97

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.