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Finding the Fourth Proportional to 871.02, 1,307.34 and 408.78

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Solution

The fourth proportional to 871.02, 1,307.34 and 408.78 is: 613.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.02 : 1,307.34 = 408.78 : x
  2. Step 2: Convert to fraction form
    871.02/1,307.34 = 408.78/x
  3. Step 3: Cross multiply
    871.02x = 1,307.34 × 408.78
  4. Step 4: Simplify right side
    871.02x = 534,414.45
  5. Step 5: Solve for x
    x = 534,414.45/871.02
  6. Step 6: Final answer
    x = 613.55

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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.