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Finding the Fourth Proportional to 139.40, 210.13 and 135.80

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Solution

The fourth proportional to 139.40, 210.13 and 135.80 is: 204.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.40 : 210.13 = 135.80 : x
  2. Step 2: Convert to fraction form
    139.40/210.13 = 135.80/x
  3. Step 3: Cross multiply
    139.40x = 210.13 × 135.80
  4. Step 4: Simplify right side
    139.40x = 28,535.65
  5. Step 5: Solve for x
    x = 28,535.65/139.40
  6. Step 6: Final answer
    x = 204.70

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.