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Finding the Fourth Proportional to 305.17, 421.11 and 172.39

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Solution

The fourth proportional to 305.17, 421.11 and 172.39 is: 237.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.17 : 421.11 = 172.39 : x
  2. Step 2: Convert to fraction form
    305.17/421.11 = 172.39/x
  3. Step 3: Cross multiply
    305.17x = 421.11 × 172.39
  4. Step 4: Simplify right side
    305.17x = 72,595.15
  5. Step 5: Solve for x
    x = 72,595.15/305.17
  6. Step 6: Final answer
    x = 237.88

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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.