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Finding the Fourth Proportional to 257.70, 386.07 and 212.14

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Solution

The fourth proportional to 257.70, 386.07 and 212.14 is: 317.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.70 : 386.07 = 212.14 : x
  2. Step 2: Convert to fraction form
    257.70/386.07 = 212.14/x
  3. Step 3: Cross multiply
    257.70x = 386.07 × 212.14
  4. Step 4: Simplify right side
    257.70x = 81,900.89
  5. Step 5: Solve for x
    x = 81,900.89/257.70
  6. Step 6: Final answer
    x = 317.81

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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.