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Finding the Fourth Proportional to 70.72, 106.15 and 34.21

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Solution

The fourth proportional to 70.72, 106.15 and 34.21 is: 51.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.72 : 106.15 = 34.21 : x
  2. Step 2: Convert to fraction form
    70.72/106.15 = 34.21/x
  3. Step 3: Cross multiply
    70.72x = 106.15 × 34.21
  4. Step 4: Simplify right side
    70.72x = 3,631.39
  5. Step 5: Solve for x
    x = 3,631.39/70.72
  6. Step 6: Final answer
    x = 51.35

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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.