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Finding the Fourth Proportional to 853.89, 1,280.78 and 487.53

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Solution

The fourth proportional to 853.89, 1,280.78 and 487.53 is: 731.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.89 : 1,280.78 = 487.53 : x
  2. Step 2: Convert to fraction form
    853.89/1,280.78 = 487.53/x
  3. Step 3: Cross multiply
    853.89x = 1,280.78 × 487.53
  4. Step 4: Simplify right side
    853.89x = 624,416.24
  5. Step 5: Solve for x
    x = 624,416.24/853.89
  6. Step 6: Final answer
    x = 731.26

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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.