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Finding the Fourth Proportional to 102.67, 154.61 and 85.66

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Solution

The fourth proportional to 102.67, 154.61 and 85.66 is: 128.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.67 : 154.61 = 85.66 : x
  2. Step 2: Convert to fraction form
    102.67/154.61 = 85.66/x
  3. Step 3: Cross multiply
    102.67x = 154.61 × 85.66
  4. Step 4: Simplify right side
    102.67x = 13,243.40
  5. Step 5: Solve for x
    x = 13,243.40/102.67
  6. Step 6: Final answer
    x = 128.99

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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.