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Finding the Fourth Proportional to 102.85, 142.05 and 79.82

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Solution

The fourth proportional to 102.85, 142.05 and 79.82 is: 110.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.85 : 142.05 = 79.82 : x
  2. Step 2: Convert to fraction form
    102.85/142.05 = 79.82/x
  3. Step 3: Cross multiply
    102.85x = 142.05 × 79.82
  4. Step 4: Simplify right side
    102.85x = 11,337.72
  5. Step 5: Solve for x
    x = 11,337.72/102.85
  6. Step 6: Final answer
    x = 110.23

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.