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Finding the Third Proportional to 31 and 70

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Solution

The third proportional to 31 and 70 is: 158.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    31 : 70 = 70 : x
  2. Step 2: Convert to fraction form
    31/70 = 70/x
  3. Step 3: Cross multiply
    31x = 70 × 70
  4. Step 4: Simplify right side
    31x = 4,900
  5. Step 5: Solve for x
    x = 4,900/31
  6. Step 6: Final answer
    x = 158.06

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Why These Related Problems?

These problems maintain the same ratio (2.26) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.