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Finding the Fourth Proportional to 257.58, 388.11 and 212.93

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Solution

The fourth proportional to 257.58, 388.11 and 212.93 is: 320.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.58 : 388.11 = 212.93 : x
  2. Step 2: Convert to fraction form
    257.58/388.11 = 212.93/x
  3. Step 3: Cross multiply
    257.58x = 388.11 × 212.93
  4. Step 4: Simplify right side
    257.58x = 82,640.26
  5. Step 5: Solve for x
    x = 82,640.26/257.58
  6. Step 6: Final answer
    x = 320.83

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.