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Finding the Fourth Proportional to 143.68, 215.33 and 78.68

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Solution

The fourth proportional to 143.68, 215.33 and 78.68 is: 117.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.68 : 215.33 = 78.68 : x
  2. Step 2: Convert to fraction form
    143.68/215.33 = 78.68/x
  3. Step 3: Cross multiply
    143.68x = 215.33 × 78.68
  4. Step 4: Simplify right side
    143.68x = 16,942.16
  5. Step 5: Solve for x
    x = 16,942.16/143.68
  6. Step 6: Final answer
    x = 117.92

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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.