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Finding the Fourth Proportional to 905.39, 1,249.41 and 491.39

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Solution

The fourth proportional to 905.39, 1,249.41 and 491.39 is: 678.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.39 : 1,249.41 = 491.39 : x
  2. Step 2: Convert to fraction form
    905.39/1,249.41 = 491.39/x
  3. Step 3: Cross multiply
    905.39x = 1,249.41 × 491.39
  4. Step 4: Simplify right side
    905.39x = 613,947.58
  5. Step 5: Solve for x
    x = 613,947.58/905.39
  6. Step 6: Final answer
    x = 678.10

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Double scale
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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.