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Finding the Fourth Proportional to 428.42, 641.54 and 342.74

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Solution

The fourth proportional to 428.42, 641.54 and 342.74 is: 513.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.42 : 641.54 = 342.74 : x
  2. Step 2: Convert to fraction form
    428.42/641.54 = 342.74/x
  3. Step 3: Cross multiply
    428.42x = 641.54 × 342.74
  4. Step 4: Simplify right side
    428.42x = 219,876.50
  5. Step 5: Solve for x
    x = 219,876.50/428.42
  6. Step 6: Final answer
    x = 513.23

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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.