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Finding the Fourth Proportional to 2,120, 3,180.20 and 581

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Solution

The fourth proportional to 2,120, 3,180.20 and 581 is: 871.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,120 : 3,180.20 = 581 : x
  2. Step 2: Convert to fraction form
    2,120/3,180.20 = 581/x
  3. Step 3: Cross multiply
    2,120x = 3,180.20 × 581
  4. Step 4: Simplify right side
    2,120x = 1,847,696.20
  5. Step 5: Solve for x
    x = 1,847,696.20/2,120
  6. Step 6: Final answer
    x = 871.55

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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.