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Finding the Fourth Proportional to 1,638.45, 2,458.31 and 761.40

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Solution

The fourth proportional to 1,638.45, 2,458.31 and 761.40 is: 1,142.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,638.45 : 2,458.31 = 761.40 : x
  2. Step 2: Convert to fraction form
    1,638.45/2,458.31 = 761.40/x
  3. Step 3: Cross multiply
    1,638.45x = 2,458.31 × 761.40
  4. Step 4: Simplify right side
    1,638.45x = 1,871,753.43
  5. Step 5: Solve for x
    x = 1,871,753.43/1,638.45
  6. Step 6: Final answer
    x = 1,142.39

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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.