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Finding the Fourth Proportional to 153.90, 229.68 and 138.60

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Solution

The fourth proportional to 153.90, 229.68 and 138.60 is: 206.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.90 : 229.68 = 138.60 : x
  2. Step 2: Convert to fraction form
    153.90/229.68 = 138.60/x
  3. Step 3: Cross multiply
    153.90x = 229.68 × 138.60
  4. Step 4: Simplify right side
    153.90x = 31,833.65
  5. Step 5: Solve for x
    x = 31,833.65/153.90
  6. Step 6: Final answer
    x = 206.85

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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.