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Finding the Fourth Proportional to 102.10, 139 and 101.20

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Solution

The fourth proportional to 102.10, 139 and 101.20 is: 137.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.10 : 139 = 101.20 : x
  2. Step 2: Convert to fraction form
    102.10/139 = 101.20/x
  3. Step 3: Cross multiply
    102.10x = 139 × 101.20
  4. Step 4: Simplify right side
    102.10x = 14,066.80
  5. Step 5: Solve for x
    x = 14,066.80/102.10
  6. Step 6: Final answer
    x = 137.77

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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.