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Finding the Fourth Proportional to 83.80, 125.60 and 47.20

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Solution

The fourth proportional to 83.80, 125.60 and 47.20 is: 70.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.80 : 125.60 = 47.20 : x
  2. Step 2: Convert to fraction form
    83.80/125.60 = 47.20/x
  3. Step 3: Cross multiply
    83.80x = 125.60 × 47.20
  4. Step 4: Simplify right side
    83.80x = 5,928.32
  5. Step 5: Solve for x
    x = 5,928.32/83.80
  6. Step 6: Final answer
    x = 70.74

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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.