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Finding the Fourth Proportional to 212.09, 318.16 and 67.81

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Solution

The fourth proportional to 212.09, 318.16 and 67.81 is: 101.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.09 : 318.16 = 67.81 : x
  2. Step 2: Convert to fraction form
    212.09/318.16 = 67.81/x
  3. Step 3: Cross multiply
    212.09x = 318.16 × 67.81
  4. Step 4: Simplify right side
    212.09x = 21,574.43
  5. Step 5: Solve for x
    x = 21,574.43/212.09
  6. Step 6: Final answer
    x = 101.72

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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.