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Finding the Fourth Proportional to 765.72, 1,148.56 and 278.80

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Solution

The fourth proportional to 765.72, 1,148.56 and 278.80 is: 418.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.72 : 1,148.56 = 278.80 : x
  2. Step 2: Convert to fraction form
    765.72/1,148.56 = 278.80/x
  3. Step 3: Cross multiply
    765.72x = 1,148.56 × 278.80
  4. Step 4: Simplify right side
    765.72x = 320,218.53
  5. Step 5: Solve for x
    x = 320,218.53/765.72
  6. Step 6: Final answer
    x = 418.19

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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.