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Finding the Fourth Proportional to 139.40, 209.20 and 58.24

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Solution

The fourth proportional to 139.40, 209.20 and 58.24 is: 87.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.40 : 209.20 = 58.24 : x
  2. Step 2: Convert to fraction form
    139.40/209.20 = 58.24/x
  3. Step 3: Cross multiply
    139.40x = 209.20 × 58.24
  4. Step 4: Simplify right side
    139.40x = 12,183.81
  5. Step 5: Solve for x
    x = 12,183.81/139.40
  6. Step 6: Final answer
    x = 87.40

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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.