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Finding the Fourth Proportional to 905.31, 1,249.33 and 491.31

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Solution

The fourth proportional to 905.31, 1,249.33 and 491.31 is: 678.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.31 : 1,249.33 = 491.31 : x
  2. Step 2: Convert to fraction form
    905.31/1,249.33 = 491.31/x
  3. Step 3: Cross multiply
    905.31x = 1,249.33 × 491.31
  4. Step 4: Simplify right side
    905.31x = 613,808.32
  5. Step 5: Solve for x
    x = 613,808.32/905.31
  6. Step 6: Final answer
    x = 678.01

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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.