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Finding the Fourth Proportional to 270.20, 405.18 and 77.78

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Solution

The fourth proportional to 270.20, 405.18 and 77.78 is: 116.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    270.20 : 405.18 = 77.78 : x
  2. Step 2: Convert to fraction form
    270.20/405.18 = 77.78/x
  3. Step 3: Cross multiply
    270.20x = 405.18 × 77.78
  4. Step 4: Simplify right side
    270.20x = 31,514.90
  5. Step 5: Solve for x
    x = 31,514.90/270.20
  6. Step 6: Final answer
    x = 116.64

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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.