Home / 2,120.94-3,178.50-821.70

Finding the Fourth Proportional to 2,120.94, 3,178.50 and 821.70

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Solution

The fourth proportional to 2,120.94, 3,178.50 and 821.70 is: 1,231.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,120.94 : 3,178.50 = 821.70 : x
  2. Step 2: Convert to fraction form
    2,120.94/3,178.50 = 821.70/x
  3. Step 3: Cross multiply
    2,120.94x = 3,178.50 × 821.70
  4. Step 4: Simplify right side
    2,120.94x = 2,611,773.45
  5. Step 5: Solve for x
    x = 2,611,773.45/2,120.94
  6. Step 6: Final answer
    x = 1,231.42

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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.