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Finding the Fourth Proportional to 879.78, 1,211.98 and 739.90

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Solution

The fourth proportional to 879.78, 1,211.98 and 739.90 is: 1,019.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.78 : 1,211.98 = 739.90 : x
  2. Step 2: Convert to fraction form
    879.78/1,211.98 = 739.90/x
  3. Step 3: Cross multiply
    879.78x = 1,211.98 × 739.90
  4. Step 4: Simplify right side
    879.78x = 896,734.24
  5. Step 5: Solve for x
    x = 896,734.24/879.78
  6. Step 6: Final answer
    x = 1,019.28

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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.