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Finding the Fourth Proportional to 146.56, 218.78 and 138.40

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Solution

The fourth proportional to 146.56, 218.78 and 138.40 is: 206.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    146.56 : 218.78 = 138.40 : x
  2. Step 2: Convert to fraction form
    146.56/218.78 = 138.40/x
  3. Step 3: Cross multiply
    146.56x = 218.78 × 138.40
  4. Step 4: Simplify right side
    146.56x = 30,279.15
  5. Step 5: Solve for x
    x = 30,279.15/146.56
  6. Step 6: Final answer
    x = 206.60

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.