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Finding the Fourth Proportional to 102.98, 140.31 and 100.76

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Solution

The fourth proportional to 102.98, 140.31 and 100.76 is: 137.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.98 : 140.31 = 100.76 : x
  2. Step 2: Convert to fraction form
    102.98/140.31 = 100.76/x
  3. Step 3: Cross multiply
    102.98x = 140.31 × 100.76
  4. Step 4: Simplify right side
    102.98x = 14,136.93
  5. Step 5: Solve for x
    x = 14,136.93/102.98
  6. Step 6: Final answer
    x = 137.28

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.