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Finding the Fourth Proportional to 103.69, 143.29 and 86.19

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Solution

The fourth proportional to 103.69, 143.29 and 86.19 is: 119.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.69 : 143.29 = 86.19 : x
  2. Step 2: Convert to fraction form
    103.69/143.29 = 86.19/x
  3. Step 3: Cross multiply
    103.69x = 143.29 × 86.19
  4. Step 4: Simplify right side
    103.69x = 12,350.17
  5. Step 5: Solve for x
    x = 12,350.17/103.69
  6. Step 6: Final answer
    x = 119.11

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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.