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Finding the Fourth Proportional to 987.30, 1,481 and 256.87

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Solution

The fourth proportional to 987.30, 1,481 and 256.87 is: 385.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.30 : 1,481 = 256.87 : x
  2. Step 2: Convert to fraction form
    987.30/1,481 = 256.87/x
  3. Step 3: Cross multiply
    987.30x = 1,481 × 256.87
  4. Step 4: Simplify right side
    987.30x = 380,424.47
  5. Step 5: Solve for x
    x = 380,424.47/987.30
  6. Step 6: Final answer
    x = 385.32

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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.