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Finding the Fourth Proportional to 102.90, 140.90 and 102.90

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Solution

The fourth proportional to 102.90, 140.90 and 102.90 is: 140.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.90 : 140.90 = 102.90 : x
  2. Step 2: Convert to fraction form
    102.90/140.90 = 102.90/x
  3. Step 3: Cross multiply
    102.90x = 140.90 × 102.90
  4. Step 4: Simplify right side
    102.90x = 14,498.61
  5. Step 5: Solve for x
    x = 14,498.61/102.90
  6. Step 6: Final answer
    x = 140.90

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.