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Finding the Fourth Proportional to 145.42, 217.92 and 138.70

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Solution

The fourth proportional to 145.42, 217.92 and 138.70 is: 207.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.42 : 217.92 = 138.70 : x
  2. Step 2: Convert to fraction form
    145.42/217.92 = 138.70/x
  3. Step 3: Cross multiply
    145.42x = 217.92 × 138.70
  4. Step 4: Simplify right side
    145.42x = 30,225.50
  5. Step 5: Solve for x
    x = 30,225.50/145.42
  6. Step 6: Final answer
    x = 207.85

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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.