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Finding the Fourth Proportional to 722.38, 996.88 and 390.81

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Solution

The fourth proportional to 722.38, 996.88 and 390.81 is: 539.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    722.38 : 996.88 = 390.81 : x
  2. Step 2: Convert to fraction form
    722.38/996.88 = 390.81/x
  3. Step 3: Cross multiply
    722.38x = 996.88 × 390.81
  4. Step 4: Simplify right side
    722.38x = 389,585.69
  5. Step 5: Solve for x
    x = 389,585.69/722.38
  6. Step 6: Final answer
    x = 539.31

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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.