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Finding the Fourth Proportional to 310.81, 428.94 and 255.39

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Solution

The fourth proportional to 310.81, 428.94 and 255.39 is: 352.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.81 : 428.94 = 255.39 : x
  2. Step 2: Convert to fraction form
    310.81/428.94 = 255.39/x
  3. Step 3: Cross multiply
    310.81x = 428.94 × 255.39
  4. Step 4: Simplify right side
    310.81x = 109,546.99
  5. Step 5: Solve for x
    x = 109,546.99/310.81
  6. Step 6: Final answer
    x = 352.46

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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.