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Finding the Fourth Proportional to 102.98, 142.17 and 71.84

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Solution

The fourth proportional to 102.98, 142.17 and 71.84 is: 99.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.98 : 142.17 = 71.84 : x
  2. Step 2: Convert to fraction form
    102.98/142.17 = 71.84/x
  3. Step 3: Cross multiply
    102.98x = 142.17 × 71.84
  4. Step 4: Simplify right side
    102.98x = 10,212.78
  5. Step 5: Solve for x
    x = 10,212.78/102.98
  6. Step 6: Final answer
    x = 99.18

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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.