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Finding the Fourth Proportional to 139.07, 208.40 and 57.87

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Solution

The fourth proportional to 139.07, 208.40 and 57.87 is: 86.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.07 : 208.40 = 57.87 : x
  2. Step 2: Convert to fraction form
    139.07/208.40 = 57.87/x
  3. Step 3: Cross multiply
    139.07x = 208.40 × 57.87
  4. Step 4: Simplify right side
    139.07x = 12,059.82
  5. Step 5: Solve for x
    x = 12,059.82/139.07
  6. Step 6: Final answer
    x = 86.72

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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.