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Finding the Fourth Proportional to 81.77, 123.09 and 70.60

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Solution

The fourth proportional to 81.77, 123.09 and 70.60 is: 106.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.77 : 123.09 = 70.60 : x
  2. Step 2: Convert to fraction form
    81.77/123.09 = 70.60/x
  3. Step 3: Cross multiply
    81.77x = 123.09 × 70.60
  4. Step 4: Simplify right side
    81.77x = 8,690.15
  5. Step 5: Solve for x
    x = 8,690.15/81.77
  6. Step 6: Final answer
    x = 106.28

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.