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Finding the Fourth Proportional to 621.55, 931.20 and 492.40

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Solution

The fourth proportional to 621.55, 931.20 and 492.40 is: 737.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.55 : 931.20 = 492.40 : x
  2. Step 2: Convert to fraction form
    621.55/931.20 = 492.40/x
  3. Step 3: Cross multiply
    621.55x = 931.20 × 492.40
  4. Step 4: Simplify right side
    621.55x = 458,522.88
  5. Step 5: Solve for x
    x = 458,522.88/621.55
  6. Step 6: Final answer
    x = 737.71

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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.