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Finding the Fourth Proportional to 103.25, 155.47 and 85.14

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Solution

The fourth proportional to 103.25, 155.47 and 85.14 is: 128.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.25 : 155.47 = 85.14 : x
  2. Step 2: Convert to fraction form
    103.25/155.47 = 85.14/x
  3. Step 3: Cross multiply
    103.25x = 155.47 × 85.14
  4. Step 4: Simplify right side
    103.25x = 13,236.72
  5. Step 5: Solve for x
    x = 13,236.72/103.25
  6. Step 6: Final answer
    x = 128.20

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.