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Finding the Fourth Proportional to 838.96, 1,257.86 and 427.30

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Solution

The fourth proportional to 838.96, 1,257.86 and 427.30 is: 640.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.96 : 1,257.86 = 427.30 : x
  2. Step 2: Convert to fraction form
    838.96/1,257.86 = 427.30/x
  3. Step 3: Cross multiply
    838.96x = 1,257.86 × 427.30
  4. Step 4: Simplify right side
    838.96x = 537,478.30
  5. Step 5: Solve for x
    x = 537,478.30/838.96
  6. Step 6: Final answer
    x = 640.65

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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.