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Finding the Fourth Proportional to 71, 106.40 and 30.40

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Solution

The fourth proportional to 71, 106.40 and 30.40 is: 45.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    71 : 106.40 = 30.40 : x
  2. Step 2: Convert to fraction form
    71/106.40 = 30.40/x
  3. Step 3: Cross multiply
    71x = 106.40 × 30.40
  4. Step 4: Simplify right side
    71x = 3,234.56
  5. Step 5: Solve for x
    x = 3,234.56/71
  6. Step 6: Final answer
    x = 45.56

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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.