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Finding the Fourth Proportional to 765.78, 1,148.13 and 278.76

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Solution

The fourth proportional to 765.78, 1,148.13 and 278.76 is: 417.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.78 : 1,148.13 = 278.76 : x
  2. Step 2: Convert to fraction form
    765.78/1,148.13 = 278.76/x
  3. Step 3: Cross multiply
    765.78x = 1,148.13 × 278.76
  4. Step 4: Simplify right side
    765.78x = 320,052.72
  5. Step 5: Solve for x
    x = 320,052.72/765.78
  6. Step 6: Final answer
    x = 417.94

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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.