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Finding the Fourth Proportional to 905.50, 1,249.59 and 491.50

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Solution

The fourth proportional to 905.50, 1,249.59 and 491.50 is: 678.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.50 : 1,249.59 = 491.50 : x
  2. Step 2: Convert to fraction form
    905.50/1,249.59 = 491.50/x
  3. Step 3: Cross multiply
    905.50x = 1,249.59 × 491.50
  4. Step 4: Simplify right side
    905.50x = 614,173.49
  5. Step 5: Solve for x
    x = 614,173.49/905.50
  6. Step 6: Final answer
    x = 678.27

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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.