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Finding the Fourth Proportional to 539.79, 809.99 and 215.39

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Solution

The fourth proportional to 539.79, 809.99 and 215.39 is: 323.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    539.79 : 809.99 = 215.39 : x
  2. Step 2: Convert to fraction form
    539.79/809.99 = 215.39/x
  3. Step 3: Cross multiply
    539.79x = 809.99 × 215.39
  4. Step 4: Simplify right side
    539.79x = 174,458.62
  5. Step 5: Solve for x
    x = 174,458.62/539.79
  6. Step 6: Final answer
    x = 323.20

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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.