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Finding the Fourth Proportional to 51.21, 70.68 and 31.55

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Solution

The fourth proportional to 51.21, 70.68 and 31.55 is: 43.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.21 : 70.68 = 31.55 : x
  2. Step 2: Convert to fraction form
    51.21/70.68 = 31.55/x
  3. Step 3: Cross multiply
    51.21x = 70.68 × 31.55
  4. Step 4: Simplify right side
    51.21x = 2,229.70
  5. Step 5: Solve for x
    x = 2,229.70/51.21
  6. Step 6: Final answer
    x = 43.54

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.