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Finding the Fourth Proportional to 939.21, 1,408.23 and 354.20

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Solution

The fourth proportional to 939.21, 1,408.23 and 354.20 is: 531.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    939.21 : 1,408.23 = 354.20 : x
  2. Step 2: Convert to fraction form
    939.21/1,408.23 = 354.20/x
  3. Step 3: Cross multiply
    939.21x = 1,408.23 × 354.20
  4. Step 4: Simplify right side
    939.21x = 498,788.02
  5. Step 5: Solve for x
    x = 498,788.02/939.21
  6. Step 6: Final answer
    x = 531.07

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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.