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Finding the Fourth Proportional to 1,611.62, 2,415.80 and 638.40

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Solution

The fourth proportional to 1,611.62, 2,415.80 and 638.40 is: 956.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,611.62 : 2,415.80 = 638.40 : x
  2. Step 2: Convert to fraction form
    1,611.62/2,415.80 = 638.40/x
  3. Step 3: Cross multiply
    1,611.62x = 2,415.80 × 638.40
  4. Step 4: Simplify right side
    1,611.62x = 1,542,246.72
  5. Step 5: Solve for x
    x = 1,542,246.72/1,611.62
  6. Step 6: Final answer
    x = 956.95

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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.