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Finding the Fourth Proportional to 143.88, 215.62 and 78.78

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Solution

The fourth proportional to 143.88, 215.62 and 78.78 is: 118.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.88 : 215.62 = 78.78 : x
  2. Step 2: Convert to fraction form
    143.88/215.62 = 78.78/x
  3. Step 3: Cross multiply
    143.88x = 215.62 × 78.78
  4. Step 4: Simplify right side
    143.88x = 16,985.91
  5. Step 5: Solve for x
    x = 16,985.91/143.88
  6. Step 6: Final answer
    x = 118.06

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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.