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Finding the Fourth Proportional to 987.32, 1,478.82 and 408.44

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Solution

The fourth proportional to 987.32, 1,478.82 and 408.44 is: 611.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.32 : 1,478.82 = 408.44 : x
  2. Step 2: Convert to fraction form
    987.32/1,478.82 = 408.44/x
  3. Step 3: Cross multiply
    987.32x = 1,478.82 × 408.44
  4. Step 4: Simplify right side
    987.32x = 604,009.24
  5. Step 5: Solve for x
    x = 604,009.24/987.32
  6. Step 6: Final answer
    x = 611.77

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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.