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Finding the Fourth Proportional to 1,003.20, 1,505.30 and 387.20

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Solution

The fourth proportional to 1,003.20, 1,505.30 and 387.20 is: 580.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,003.20 : 1,505.30 = 387.20 : x
  2. Step 2: Convert to fraction form
    1,003.20/1,505.30 = 387.20/x
  3. Step 3: Cross multiply
    1,003.20x = 1,505.30 × 387.20
  4. Step 4: Simplify right side
    1,003.20x = 582,842.70
  5. Step 5: Solve for x
    x = 582,842.70/1,003.20
  6. Step 6: Final answer
    x = 580.98

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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.