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Finding the Fourth Proportional to 840.87, 1,259.73 and 429.57

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Solution

The fourth proportional to 840.87, 1,259.73 and 429.57 is: 643.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.87 : 1,259.73 = 429.57 : x
  2. Step 2: Convert to fraction form
    840.87/1,259.73 = 429.57/x
  3. Step 3: Cross multiply
    840.87x = 1,259.73 × 429.57
  4. Step 4: Simplify right side
    840.87x = 541,142.22
  5. Step 5: Solve for x
    x = 541,142.22/840.87
  6. Step 6: Final answer
    x = 643.55

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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.