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Finding the Fourth Proportional to 1,392.78, 2,089.41 and 419.10

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Solution

The fourth proportional to 1,392.78, 2,089.41 and 419.10 is: 628.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,392.78 : 2,089.41 = 419.10 : x
  2. Step 2: Convert to fraction form
    1,392.78/2,089.41 = 419.10/x
  3. Step 3: Cross multiply
    1,392.78x = 2,089.41 × 419.10
  4. Step 4: Simplify right side
    1,392.78x = 875,671.73
  5. Step 5: Solve for x
    x = 875,671.73/1,392.78
  6. Step 6: Final answer
    x = 628.72

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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.