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Finding the Fourth Proportional to 381.65, 572.40 and 121.61

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Solution

The fourth proportional to 381.65, 572.40 and 121.61 is: 182.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.65 : 572.40 = 121.61 : x
  2. Step 2: Convert to fraction form
    381.65/572.40 = 121.61/x
  3. Step 3: Cross multiply
    381.65x = 572.40 × 121.61
  4. Step 4: Simplify right side
    381.65x = 69,611.45
  5. Step 5: Solve for x
    x = 69,611.45/381.65
  6. Step 6: Final answer
    x = 182.40

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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.