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Finding the Fourth Proportional to 722.45, 996.99 and 390.88

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Solution

The fourth proportional to 722.45, 996.99 and 390.88 is: 539.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    722.45 : 996.99 = 390.88 : x
  2. Step 2: Convert to fraction form
    722.45/996.99 = 390.88/x
  3. Step 3: Cross multiply
    722.45x = 996.99 × 390.88
  4. Step 4: Simplify right side
    722.45x = 389,706.57
  5. Step 5: Solve for x
    x = 389,706.57/722.45
  6. Step 6: Final answer
    x = 539.42

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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.