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Finding the Fourth Proportional to 310.76, 428.84 and 172.76

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Solution

The fourth proportional to 310.76, 428.84 and 172.76 is: 238.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.76 : 428.84 = 172.76 : x
  2. Step 2: Convert to fraction form
    310.76/428.84 = 172.76/x
  3. Step 3: Cross multiply
    310.76x = 428.84 × 172.76
  4. Step 4: Simplify right side
    310.76x = 74,086.40
  5. Step 5: Solve for x
    x = 74,086.40/310.76
  6. Step 6: Final answer
    x = 238.40

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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.