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Finding the Fourth Proportional to 212.49, 293.15 and 138.78

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Solution

The fourth proportional to 212.49, 293.15 and 138.78 is: 191.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.49 : 293.15 = 138.78 : x
  2. Step 2: Convert to fraction form
    212.49/293.15 = 138.78/x
  3. Step 3: Cross multiply
    212.49x = 293.15 × 138.78
  4. Step 4: Simplify right side
    212.49x = 40,682.66
  5. Step 5: Solve for x
    x = 40,682.66/212.49
  6. Step 6: Final answer
    x = 191.46

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.