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Finding the Fourth Proportional to 1,331.88, 1,998.01 and 638.90

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Solution

The fourth proportional to 1,331.88, 1,998.01 and 638.90 is: 958.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,331.88 : 1,998.01 = 638.90 : x
  2. Step 2: Convert to fraction form
    1,331.88/1,998.01 = 638.90/x
  3. Step 3: Cross multiply
    1,331.88x = 1,998.01 × 638.90
  4. Step 4: Simplify right side
    1,331.88x = 1,276,518.60
  5. Step 5: Solve for x
    x = 1,276,518.60/1,331.88
  6. Step 6: Final answer
    x = 958.43

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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.