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Finding the Fourth Proportional to 212.19, 318.28 and 130.78

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Solution

The fourth proportional to 212.19, 318.28 and 130.78 is: 196.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.19 : 318.28 = 130.78 : x
  2. Step 2: Convert to fraction form
    212.19/318.28 = 130.78/x
  3. Step 3: Cross multiply
    212.19x = 318.28 × 130.78
  4. Step 4: Simplify right side
    212.19x = 41,624.97
  5. Step 5: Solve for x
    x = 41,624.97/212.19
  6. Step 6: Final answer
    x = 196.17

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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.