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Finding the Fourth Proportional to 103.76, 143.36 and 87.98

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Solution

The fourth proportional to 103.76, 143.36 and 87.98 is: 121.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.76 : 143.36 = 87.98 : x
  2. Step 2: Convert to fraction form
    103.76/143.36 = 87.98/x
  3. Step 3: Cross multiply
    103.76x = 143.36 × 87.98
  4. Step 4: Simplify right side
    103.76x = 12,611.66
  5. Step 5: Solve for x
    x = 12,611.66/103.76
  6. Step 6: Final answer
    x = 121.55

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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.