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Finding the Fourth Proportional to 68.34, 102.48 and 31.78

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Solution

The fourth proportional to 68.34, 102.48 and 31.78 is: 47.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.34 : 102.48 = 31.78 : x
  2. Step 2: Convert to fraction form
    68.34/102.48 = 31.78/x
  3. Step 3: Cross multiply
    68.34x = 102.48 × 31.78
  4. Step 4: Simplify right side
    68.34x = 3,256.81
  5. Step 5: Solve for x
    x = 3,256.81/68.34
  6. Step 6: Final answer
    x = 47.66

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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.