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Finding the Fourth Proportional to 103.41, 155.25 and 86.40

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Solution

The fourth proportional to 103.41, 155.25 and 86.40 is: 129.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.41 : 155.25 = 86.40 : x
  2. Step 2: Convert to fraction form
    103.41/155.25 = 86.40/x
  3. Step 3: Cross multiply
    103.41x = 155.25 × 86.40
  4. Step 4: Simplify right side
    103.41x = 13,413.60
  5. Step 5: Solve for x
    x = 13,413.60/103.41
  6. Step 6: Final answer
    x = 129.71

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.