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Finding the Fourth Proportional to 621.60, 931.36 and 438.11

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Solution

The fourth proportional to 621.60, 931.36 and 438.11 is: 656.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.60 : 931.36 = 438.11 : x
  2. Step 2: Convert to fraction form
    621.60/931.36 = 438.11/x
  3. Step 3: Cross multiply
    621.60x = 931.36 × 438.11
  4. Step 4: Simplify right side
    621.60x = 408,031.28
  5. Step 5: Solve for x
    x = 408,031.28/621.60
  6. Step 6: Final answer
    x = 656.42

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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.