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Finding the Fourth Proportional to 381.80, 572.70 and 138.32

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Solution

The fourth proportional to 381.80, 572.70 and 138.32 is: 207.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.80 : 572.70 = 138.32 : x
  2. Step 2: Convert to fraction form
    381.80/572.70 = 138.32/x
  3. Step 3: Cross multiply
    381.80x = 572.70 × 138.32
  4. Step 4: Simplify right side
    381.80x = 79,216.51
  5. Step 5: Solve for x
    x = 79,216.51/381.80
  6. Step 6: Final answer
    x = 207.48

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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.