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Finding the Fourth Proportional to 103.25, 142.05 and 90.95

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Solution

The fourth proportional to 103.25, 142.05 and 90.95 is: 125.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.25 : 142.05 = 90.95 : x
  2. Step 2: Convert to fraction form
    103.25/142.05 = 90.95/x
  3. Step 3: Cross multiply
    103.25x = 142.05 × 90.95
  4. Step 4: Simplify right side
    103.25x = 12,918.74
  5. Step 5: Solve for x
    x = 12,918.74/103.25
  6. Step 6: Final answer
    x = 125.13

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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.