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Finding the Fourth Proportional to 139.30, 209 and 58.18

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Solution

The fourth proportional to 139.30, 209 and 58.18 is: 87.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.30 : 209 = 58.18 : x
  2. Step 2: Convert to fraction form
    139.30/209 = 58.18/x
  3. Step 3: Cross multiply
    139.30x = 209 × 58.18
  4. Step 4: Simplify right side
    139.30x = 12,159.62
  5. Step 5: Solve for x
    x = 12,159.62/139.30
  6. Step 6: Final answer
    x = 87.29

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.