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Finding the Fourth Proportional to 254.39, 381.65 and 81.07

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Solution

The fourth proportional to 254.39, 381.65 and 81.07 is: 121.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    254.39 : 381.65 = 81.07 : x
  2. Step 2: Convert to fraction form
    254.39/381.65 = 81.07/x
  3. Step 3: Cross multiply
    254.39x = 381.65 × 81.07
  4. Step 4: Simplify right side
    254.39x = 30,939.01
  5. Step 5: Solve for x
    x = 30,939.01/254.39
  6. Step 6: Final answer
    x = 121.62

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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.