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Finding the Fourth Proportional to 139.41, 209.21 and 58.28

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Solution

The fourth proportional to 139.41, 209.21 and 58.28 is: 87.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.41 : 209.21 = 58.28 : x
  2. Step 2: Convert to fraction form
    139.41/209.21 = 58.28/x
  3. Step 3: Cross multiply
    139.41x = 209.21 × 58.28
  4. Step 4: Simplify right side
    139.41x = 12,191.42
  5. Step 5: Solve for x
    x = 12,191.42/139.41
  6. Step 6: Final answer
    x = 87.45

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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.