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Finding the Fourth Proportional to 390.69, 539.09 and 233.31

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Solution

The fourth proportional to 390.69, 539.09 and 233.31 is: 321.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.69 : 539.09 = 233.31 : x
  2. Step 2: Convert to fraction form
    390.69/539.09 = 233.31/x
  3. Step 3: Cross multiply
    390.69x = 539.09 × 233.31
  4. Step 4: Simplify right side
    390.69x = 125,772.98
  5. Step 5: Solve for x
    x = 125,772.98/390.69
  6. Step 6: Final answer
    x = 321.93

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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.