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Finding the Fourth Proportional to 809.89, 1,118.39 and 515.25

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Solution

The fourth proportional to 809.89, 1,118.39 and 515.25 is: 711.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.89 : 1,118.39 = 515.25 : x
  2. Step 2: Convert to fraction form
    809.89/1,118.39 = 515.25/x
  3. Step 3: Cross multiply
    809.89x = 1,118.39 × 515.25
  4. Step 4: Simplify right side
    809.89x = 576,247.87
  5. Step 5: Solve for x
    x = 576,247.87/809.89
  6. Step 6: Final answer
    x = 711.52

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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.