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Finding the Fourth Proportional to 765.85, 1,148.89 and 278.79

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Solution

The fourth proportional to 765.85, 1,148.89 and 278.79 is: 418.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.85 : 1,148.89 = 278.79 : x
  2. Step 2: Convert to fraction form
    765.85/1,148.89 = 278.79/x
  3. Step 3: Cross multiply
    765.85x = 1,148.89 × 278.79
  4. Step 4: Simplify right side
    765.85x = 320,299.04
  5. Step 5: Solve for x
    x = 320,299.04/765.85
  6. Step 6: Final answer
    x = 418.23

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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.