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Finding the Fourth Proportional to 639.09, 881.12 and 428.93

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Solution

The fourth proportional to 639.09, 881.12 and 428.93 is: 591.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.09 : 881.12 = 428.93 : x
  2. Step 2: Convert to fraction form
    639.09/881.12 = 428.93/x
  3. Step 3: Cross multiply
    639.09x = 881.12 × 428.93
  4. Step 4: Simplify right side
    639.09x = 377,938.80
  5. Step 5: Solve for x
    x = 377,938.80/639.09
  6. Step 6: Final answer
    x = 591.37

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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.