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Finding the Fourth Proportional to 866.20, 1,299.30 and 520.60

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Solution

The fourth proportional to 866.20, 1,299.30 and 520.60 is: 780.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    866.20 : 1,299.30 = 520.60 : x
  2. Step 2: Convert to fraction form
    866.20/1,299.30 = 520.60/x
  3. Step 3: Cross multiply
    866.20x = 1,299.30 × 520.60
  4. Step 4: Simplify right side
    866.20x = 676,415.58
  5. Step 5: Solve for x
    x = 676,415.58/866.20
  6. Step 6: Final answer
    x = 780.90

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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.