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Finding the Fourth Proportional to 212.63, 318.96 and 68.40

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Solution

The fourth proportional to 212.63, 318.96 and 68.40 is: 102.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.63 : 318.96 = 68.40 : x
  2. Step 2: Convert to fraction form
    212.63/318.96 = 68.40/x
  3. Step 3: Cross multiply
    212.63x = 318.96 × 68.40
  4. Step 4: Simplify right side
    212.63x = 21,816.86
  5. Step 5: Solve for x
    x = 21,816.86/212.63
  6. Step 6: Final answer
    x = 102.61

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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.