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Finding the Fourth Proportional to 109.13, 163.54 and 84.78

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Solution

The fourth proportional to 109.13, 163.54 and 84.78 is: 127.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.13 : 163.54 = 84.78 : x
  2. Step 2: Convert to fraction form
    109.13/163.54 = 84.78/x
  3. Step 3: Cross multiply
    109.13x = 163.54 × 84.78
  4. Step 4: Simplify right side
    109.13x = 13,864.91
  5. Step 5: Solve for x
    x = 13,864.91/109.13
  6. Step 6: Final answer
    x = 127.05

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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.