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Finding the Fourth Proportional to 765.28, 1,147.68 and 278.32

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Solution

The fourth proportional to 765.28, 1,147.68 and 278.32 is: 417.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.28 : 1,147.68 = 278.32 : x
  2. Step 2: Convert to fraction form
    765.28/1,147.68 = 278.32/x
  3. Step 3: Cross multiply
    765.28x = 1,147.68 × 278.32
  4. Step 4: Simplify right side
    765.28x = 319,422.30
  5. Step 5: Solve for x
    x = 319,422.30/765.28
  6. Step 6: Final answer
    x = 417.39

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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.