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Finding the Fourth Proportional to 921.39, 1,381.91 and 272.13

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Solution

The fourth proportional to 921.39, 1,381.91 and 272.13 is: 408.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.39 : 1,381.91 = 272.13 : x
  2. Step 2: Convert to fraction form
    921.39/1,381.91 = 272.13/x
  3. Step 3: Cross multiply
    921.39x = 1,381.91 × 272.13
  4. Step 4: Simplify right side
    921.39x = 376,057.81
  5. Step 5: Solve for x
    x = 376,057.81/921.39
  6. Step 6: Final answer
    x = 408.14

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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.