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Finding the Fourth Proportional to 81.70, 112.74 and 63.25

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Solution

The fourth proportional to 81.70, 112.74 and 63.25 is: 87.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.70 : 112.74 = 63.25 : x
  2. Step 2: Convert to fraction form
    81.70/112.74 = 63.25/x
  3. Step 3: Cross multiply
    81.70x = 112.74 × 63.25
  4. Step 4: Simplify right side
    81.70x = 7,130.81
  5. Step 5: Solve for x
    x = 7,130.81/81.70
  6. Step 6: Final answer
    x = 87.28

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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.