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Finding the Fourth Proportional to 1,821.10, 2,731.26 and 781.66

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Solution

The fourth proportional to 1,821.10, 2,731.26 and 781.66 is: 1,172.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,821.10 : 2,731.26 = 781.66 : x
  2. Step 2: Convert to fraction form
    1,821.10/2,731.26 = 781.66/x
  3. Step 3: Cross multiply
    1,821.10x = 2,731.26 × 781.66
  4. Step 4: Simplify right side
    1,821.10x = 2,134,916.69
  5. Step 5: Solve for x
    x = 2,134,916.69/1,821.10
  6. Step 6: Final answer
    x = 1,172.32

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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.