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Finding the Fourth Proportional to 103.55, 143.05 and 72.55

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Solution

The fourth proportional to 103.55, 143.05 and 72.55 is: 100.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.55 : 143.05 = 72.55 : x
  2. Step 2: Convert to fraction form
    103.55/143.05 = 72.55/x
  3. Step 3: Cross multiply
    103.55x = 143.05 × 72.55
  4. Step 4: Simplify right side
    103.55x = 10,378.28
  5. Step 5: Solve for x
    x = 10,378.28/103.55
  6. Step 6: Final answer
    x = 100.22

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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.