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Finding the Fourth Proportional to 310.72, 428.40 and 254.80

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Solution

The fourth proportional to 310.72, 428.40 and 254.80 is: 351.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.72 : 428.40 = 254.80 : x
  2. Step 2: Convert to fraction form
    310.72/428.40 = 254.80/x
  3. Step 3: Cross multiply
    310.72x = 428.40 × 254.80
  4. Step 4: Simplify right side
    310.72x = 109,156.32
  5. Step 5: Solve for x
    x = 109,156.32/310.72
  6. Step 6: Final answer
    x = 351.30

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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.