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Finding the Fourth Proportional to 103.21, 142.36 and 83.57

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Solution

The fourth proportional to 103.21, 142.36 and 83.57 is: 115.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.21 : 142.36 = 83.57 : x
  2. Step 2: Convert to fraction form
    103.21/142.36 = 83.57/x
  3. Step 3: Cross multiply
    103.21x = 142.36 × 83.57
  4. Step 4: Simplify right side
    103.21x = 11,896.10
  5. Step 5: Solve for x
    x = 11,896.10/103.21
  6. Step 6: Final answer
    x = 115.26

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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.