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Finding the Fourth Proportional to 809.99, 1,211.89 and 445.03

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Solution

The fourth proportional to 809.99, 1,211.89 and 445.03 is: 665.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.99 : 1,211.89 = 445.03 : x
  2. Step 2: Convert to fraction form
    809.99/1,211.89 = 445.03/x
  3. Step 3: Cross multiply
    809.99x = 1,211.89 × 445.03
  4. Step 4: Simplify right side
    809.99x = 539,327.41
  5. Step 5: Solve for x
    x = 539,327.41/809.99
  6. Step 6: Final answer
    x = 665.84

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.