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Finding the Fourth Proportional to 135.15, 202.90 and 80.40

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Solution

The fourth proportional to 135.15, 202.90 and 80.40 is: 120.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.15 : 202.90 = 80.40 : x
  2. Step 2: Convert to fraction form
    135.15/202.90 = 80.40/x
  3. Step 3: Cross multiply
    135.15x = 202.90 × 80.40
  4. Step 4: Simplify right side
    135.15x = 16,313.16
  5. Step 5: Solve for x
    x = 16,313.16/135.15
  6. Step 6: Final answer
    x = 120.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.