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Finding the Fourth Proportional to 765.12, 1,146.87 and 439.80

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Solution

The fourth proportional to 765.12, 1,146.87 and 439.80 is: 659.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.12 : 1,146.87 = 439.80 : x
  2. Step 2: Convert to fraction form
    765.12/1,146.87 = 439.80/x
  3. Step 3: Cross multiply
    765.12x = 1,146.87 × 439.80
  4. Step 4: Simplify right side
    765.12x = 504,393.43
  5. Step 5: Solve for x
    x = 504,393.43/765.12
  6. Step 6: Final answer
    x = 659.23

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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.