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Finding the Fourth Proportional to 838.50, 1,257.88 and 422.21

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Solution

The fourth proportional to 838.50, 1,257.88 and 422.21 is: 633.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.50 : 1,257.88 = 422.21 : x
  2. Step 2: Convert to fraction form
    838.50/1,257.88 = 422.21/x
  3. Step 3: Cross multiply
    838.50x = 1,257.88 × 422.21
  4. Step 4: Simplify right side
    838.50x = 531,092.40
  5. Step 5: Solve for x
    x = 531,092.40/838.50
  6. Step 6: Final answer
    x = 633.38

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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.