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Finding the Fourth Proportional to 105.56, 145.50 and 84.78

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Solution

The fourth proportional to 105.56, 145.50 and 84.78 is: 116.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.56 : 145.50 = 84.78 : x
  2. Step 2: Convert to fraction form
    105.56/145.50 = 84.78/x
  3. Step 3: Cross multiply
    105.56x = 145.50 × 84.78
  4. Step 4: Simplify right side
    105.56x = 12,335.49
  5. Step 5: Solve for x
    x = 12,335.49/105.56
  6. Step 6: Final answer
    x = 116.86

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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.