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Finding the Fourth Proportional to 143.80, 215.42 and 71.72

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Solution

The fourth proportional to 143.80, 215.42 and 71.72 is: 107.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.80 : 215.42 = 71.72 : x
  2. Step 2: Convert to fraction form
    143.80/215.42 = 71.72/x
  3. Step 3: Cross multiply
    143.80x = 215.42 × 71.72
  4. Step 4: Simplify right side
    143.80x = 15,449.92
  5. Step 5: Solve for x
    x = 15,449.92/143.80
  6. Step 6: Final answer
    x = 107.44

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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.