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Finding the Fourth Proportional to 998.06, 1,377.09 and 643.41

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Solution

The fourth proportional to 998.06, 1,377.09 and 643.41 is: 887.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.06 : 1,377.09 = 643.41 : x
  2. Step 2: Convert to fraction form
    998.06/1,377.09 = 643.41/x
  3. Step 3: Cross multiply
    998.06x = 1,377.09 × 643.41
  4. Step 4: Simplify right side
    998.06x = 886,033.48
  5. Step 5: Solve for x
    x = 886,033.48/998.06
  6. Step 6: Final answer
    x = 887.76

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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.