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Finding the Fourth Proportional to 145.96, 218.60 and 138.78

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Solution

The fourth proportional to 145.96, 218.60 and 138.78 is: 207.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.96 : 218.60 = 138.78 : x
  2. Step 2: Convert to fraction form
    145.96/218.60 = 138.78/x
  3. Step 3: Cross multiply
    145.96x = 218.60 × 138.78
  4. Step 4: Simplify right side
    145.96x = 30,337.31
  5. Step 5: Solve for x
    x = 30,337.31/145.96
  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.