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Finding the Fourth Proportional to 207.70, 311.55 and 142.90

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Solution

The fourth proportional to 207.70, 311.55 and 142.90 is: 214.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.70 : 311.55 = 142.90 : x
  2. Step 2: Convert to fraction form
    207.70/311.55 = 142.90/x
  3. Step 3: Cross multiply
    207.70x = 311.55 × 142.90
  4. Step 4: Simplify right side
    207.70x = 44,520.50
  5. Step 5: Solve for x
    x = 44,520.50/207.70
  6. Step 6: Final answer
    x = 214.35

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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.