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Finding the Fourth Proportional to 142.75, 214.17 and 78.67

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Solution

The fourth proportional to 142.75, 214.17 and 78.67 is: 118.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.75 : 214.17 = 78.67 : x
  2. Step 2: Convert to fraction form
    142.75/214.17 = 78.67/x
  3. Step 3: Cross multiply
    142.75x = 214.17 × 78.67
  4. Step 4: Simplify right side
    142.75x = 16,848.75
  5. Step 5: Solve for x
    x = 16,848.75/142.75
  6. Step 6: Final answer
    x = 118.03

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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.