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Finding the Fourth Proportional to 998.21, 1,378.40 and 625.83

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Solution

The fourth proportional to 998.21, 1,378.40 and 625.83 is: 864.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.21 : 1,378.40 = 625.83 : x
  2. Step 2: Convert to fraction form
    998.21/1,378.40 = 625.83/x
  3. Step 3: Cross multiply
    998.21x = 1,378.40 × 625.83
  4. Step 4: Simplify right side
    998.21x = 862,634.05
  5. Step 5: Solve for x
    x = 862,634.05/998.21
  6. Step 6: Final answer
    x = 864.19

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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.