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Finding the Fourth Proportional to 987.29, 1,480.99 and 256.85

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Solution

The fourth proportional to 987.29, 1,480.99 and 256.85 is: 385.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.29 : 1,480.99 = 256.85 : x
  2. Step 2: Convert to fraction form
    987.29/1,480.99 = 256.85/x
  3. Step 3: Cross multiply
    987.29x = 1,480.99 × 256.85
  4. Step 4: Simplify right side
    987.29x = 380,392.28
  5. Step 5: Solve for x
    x = 380,392.28/987.29
  6. Step 6: Final answer
    x = 385.29

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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.