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Finding the Fourth Proportional to 1,278.43, 1,763.93 and 780.77

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Solution

The fourth proportional to 1,278.43, 1,763.93 and 780.77 is: 1,077.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.43 : 1,763.93 = 780.77 : x
  2. Step 2: Convert to fraction form
    1,278.43/1,763.93 = 780.77/x
  3. Step 3: Cross multiply
    1,278.43x = 1,763.93 × 780.77
  4. Step 4: Simplify right side
    1,278.43x = 1,377,229.99
  5. Step 5: Solve for x
    x = 1,377,229.99/1,278.43
  6. Step 6: Final answer
    x = 1,077.28

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.