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Finding the Fourth Proportional to 143.42, 215.14 and 78.41

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Solution

The fourth proportional to 143.42, 215.14 and 78.41 is: 117.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.42 : 215.14 = 78.41 : x
  2. Step 2: Convert to fraction form
    143.42/215.14 = 78.41/x
  3. Step 3: Cross multiply
    143.42x = 215.14 × 78.41
  4. Step 4: Simplify right side
    143.42x = 16,869.13
  5. Step 5: Solve for x
    x = 16,869.13/143.42
  6. Step 6: Final answer
    x = 117.62

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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.