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Finding the Fourth Proportional to 154.56, 213.40 and 139.90

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Solution

The fourth proportional to 154.56, 213.40 and 139.90 is: 193.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.56 : 213.40 = 139.90 : x
  2. Step 2: Convert to fraction form
    154.56/213.40 = 139.90/x
  3. Step 3: Cross multiply
    154.56x = 213.40 × 139.90
  4. Step 4: Simplify right side
    154.56x = 29,854.66
  5. Step 5: Solve for x
    x = 29,854.66/154.56
  6. Step 6: Final answer
    x = 193.16

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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.