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Finding the Fourth Proportional to 103.24, 142.40 and 80

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Solution

The fourth proportional to 103.24, 142.40 and 80 is: 110.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.24 : 142.40 = 80 : x
  2. Step 2: Convert to fraction form
    103.24/142.40 = 80/x
  3. Step 3: Cross multiply
    103.24x = 142.40 × 80
  4. Step 4: Simplify right side
    103.24x = 11,392
  5. Step 5: Solve for x
    x = 11,392/103.24
  6. Step 6: Final answer
    x = 110.34

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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.