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Finding the Fourth Proportional to 1,387.30, 2,081.04 and 521.56

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Solution

The fourth proportional to 1,387.30, 2,081.04 and 521.56 is: 782.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,387.30 : 2,081.04 = 521.56 : x
  2. Step 2: Convert to fraction form
    1,387.30/2,081.04 = 521.56/x
  3. Step 3: Cross multiply
    1,387.30x = 2,081.04 × 521.56
  4. Step 4: Simplify right side
    1,387.30x = 1,085,387.22
  5. Step 5: Solve for x
    x = 1,085,387.22/1,387.30
  6. Step 6: Final answer
    x = 782.37

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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.