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Finding the Fourth Proportional to 1,638.42, 2,454.99 and 815.86

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Solution

The fourth proportional to 1,638.42, 2,454.99 and 815.86 is: 1,222.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,638.42 : 2,454.99 = 815.86 : x
  2. Step 2: Convert to fraction form
    1,638.42/2,454.99 = 815.86/x
  3. Step 3: Cross multiply
    1,638.42x = 2,454.99 × 815.86
  4. Step 4: Simplify right side
    1,638.42x = 2,002,928.14
  5. Step 5: Solve for x
    x = 2,002,928.14/1,638.42
  6. Step 6: Final answer
    x = 1,222.48

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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.