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Finding the Fourth Proportional to 1,238.79, 1,857 and 458.58

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Solution

The fourth proportional to 1,238.79, 1,857 and 458.58 is: 687.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.79 : 1,857 = 458.58 : x
  2. Step 2: Convert to fraction form
    1,238.79/1,857 = 458.58/x
  3. Step 3: Cross multiply
    1,238.79x = 1,857 × 458.58
  4. Step 4: Simplify right side
    1,238.79x = 851,583.06
  5. Step 5: Solve for x
    x = 851,583.06/1,238.79
  6. Step 6: Final answer
    x = 687.43

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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.