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Finding the Fourth Proportional to 81.60, 112.63 and 57.05

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Solution

The fourth proportional to 81.60, 112.63 and 57.05 is: 78.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.60 : 112.63 = 57.05 : x
  2. Step 2: Convert to fraction form
    81.60/112.63 = 57.05/x
  3. Step 3: Cross multiply
    81.60x = 112.63 × 57.05
  4. Step 4: Simplify right side
    81.60x = 6,425.05
  5. Step 5: Solve for x
    x = 6,425.05/81.60
  6. Step 6: Final answer
    x = 78.74

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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.