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Finding the Fourth Proportional to 857.39, 1,286.48 and 418.77

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Solution

The fourth proportional to 857.39, 1,286.48 and 418.77 is: 628.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.39 : 1,286.48 = 418.77 : x
  2. Step 2: Convert to fraction form
    857.39/1,286.48 = 418.77/x
  3. Step 3: Cross multiply
    857.39x = 1,286.48 × 418.77
  4. Step 4: Simplify right side
    857.39x = 538,740.28
  5. Step 5: Solve for x
    x = 538,740.28/857.39
  6. Step 6: Final answer
    x = 628.35

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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.