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Finding the Fourth Proportional to 103.50, 142.81 and 77.18

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Solution

The fourth proportional to 103.50, 142.81 and 77.18 is: 106.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.50 : 142.81 = 77.18 : x
  2. Step 2: Convert to fraction form
    103.50/142.81 = 77.18/x
  3. Step 3: Cross multiply
    103.50x = 142.81 × 77.18
  4. Step 4: Simplify right side
    103.50x = 11,022.24
  5. Step 5: Solve for x
    x = 11,022.24/103.50
  6. Step 6: Final answer
    x = 106.50

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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.