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Finding the Fourth Proportional to 212.80, 319.08 and 68.48

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Solution

The fourth proportional to 212.80, 319.08 and 68.48 is: 102.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.80 : 319.08 = 68.48 : x
  2. Step 2: Convert to fraction form
    212.80/319.08 = 68.48/x
  3. Step 3: Cross multiply
    212.80x = 319.08 × 68.48
  4. Step 4: Simplify right side
    212.80x = 21,850.60
  5. Step 5: Solve for x
    x = 21,850.60/212.80
  6. Step 6: Final answer
    x = 102.68

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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.