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Finding the Fourth Proportional to 765.79, 1,149.14 and 278.87

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Solution

The fourth proportional to 765.79, 1,149.14 and 278.87 is: 418.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.79 : 1,149.14 = 278.87 : x
  2. Step 2: Convert to fraction form
    765.79/1,149.14 = 278.87/x
  3. Step 3: Cross multiply
    765.79x = 1,149.14 × 278.87
  4. Step 4: Simplify right side
    765.79x = 320,459.28
  5. Step 5: Solve for x
    x = 320,459.28/765.79
  6. Step 6: Final answer
    x = 418.47

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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.