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Finding the Fourth Proportional to 8,139.40, 12,209.10 and 7,318.60

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Solution

The fourth proportional to 8,139.40, 12,209.10 and 7,318.60 is: 10,977.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    8,139.40 : 12,209.10 = 7,318.60 : x
  2. Step 2: Convert to fraction form
    8,139.40/12,209.10 = 7,318.60/x
  3. Step 3: Cross multiply
    8,139.40x = 12,209.10 × 7,318.60
  4. Step 4: Simplify right side
    8,139.40x = 89,353,519.26
  5. Step 5: Solve for x
    x = 89,353,519.26/8,139.40
  6. Step 6: Final answer
    x = 10,977.90

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Similar ratio
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1.5x scale

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.