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Finding the Fourth Proportional to 109.62, 151.20 and 84.78

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Solution

The fourth proportional to 109.62, 151.20 and 84.78 is: 116.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.62 : 151.20 = 84.78 : x
  2. Step 2: Convert to fraction form
    109.62/151.20 = 84.78/x
  3. Step 3: Cross multiply
    109.62x = 151.20 × 84.78
  4. Step 4: Simplify right side
    109.62x = 12,818.74
  5. Step 5: Solve for x
    x = 12,818.74/109.62
  6. Step 6: Final answer
    x = 116.94

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.