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Finding the Fourth Proportional to 51.39, 70.91 and 31.71

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Solution

The fourth proportional to 51.39, 70.91 and 31.71 is: 43.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.39 : 70.91 = 31.71 : x
  2. Step 2: Convert to fraction form
    51.39/70.91 = 31.71/x
  3. Step 3: Cross multiply
    51.39x = 70.91 × 31.71
  4. Step 4: Simplify right side
    51.39x = 2,248.40
  5. Step 5: Solve for x
    x = 2,248.40/51.39
  6. Step 6: Final answer
    x = 43.75

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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.