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Finding the Fourth Proportional to 103.40, 154.49 and 85.13

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Solution

The fourth proportional to 103.40, 154.49 and 85.13 is: 127.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.40 : 154.49 = 85.13 : x
  2. Step 2: Convert to fraction form
    103.40/154.49 = 85.13/x
  3. Step 3: Cross multiply
    103.40x = 154.49 × 85.13
  4. Step 4: Simplify right side
    103.40x = 13,151.73
  5. Step 5: Solve for x
    x = 13,151.73/103.40
  6. Step 6: Final answer
    x = 127.19

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.