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Finding the Fourth Proportional to 905.57, 1,249.68 and 491.57

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Solution

The fourth proportional to 905.57, 1,249.68 and 491.57 is: 678.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.57 : 1,249.68 = 491.57 : x
  2. Step 2: Convert to fraction form
    905.57/1,249.68 = 491.57/x
  3. Step 3: Cross multiply
    905.57x = 1,249.68 × 491.57
  4. Step 4: Simplify right side
    905.57x = 614,296.49
  5. Step 5: Solve for x
    x = 614,296.49/905.57
  6. Step 6: Final answer
    x = 678.36

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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.