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Finding the Fourth Proportional to 428.50, 642.77 and 255.24

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Solution

The fourth proportional to 428.50, 642.77 and 255.24 is: 382.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.50 : 642.77 = 255.24 : x
  2. Step 2: Convert to fraction form
    428.50/642.77 = 255.24/x
  3. Step 3: Cross multiply
    428.50x = 642.77 × 255.24
  4. Step 4: Simplify right side
    428.50x = 164,060.30
  5. Step 5: Solve for x
    x = 164,060.30/428.50
  6. Step 6: Final answer
    x = 382.87

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.