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Finding the Fourth Proportional to 905.12, 1,249.09 and 491.12

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Solution

The fourth proportional to 905.12, 1,249.09 and 491.12 is: 677.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.12 : 1,249.09 = 491.12 : x
  2. Step 2: Convert to fraction form
    905.12/1,249.09 = 491.12/x
  3. Step 3: Cross multiply
    905.12x = 1,249.09 × 491.12
  4. Step 4: Simplify right side
    905.12x = 613,453.08
  5. Step 5: Solve for x
    x = 613,453.08/905.12
  6. Step 6: Final answer
    x = 677.76

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1.5x scale

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.