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Finding the Fourth Proportional to 722.31, 996.80 and 390.74

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Solution

The fourth proportional to 722.31, 996.80 and 390.74 is: 539.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    722.31 : 996.80 = 390.74 : x
  2. Step 2: Convert to fraction form
    722.31/996.80 = 390.74/x
  3. Step 3: Cross multiply
    722.31x = 996.80 × 390.74
  4. Step 4: Simplify right side
    722.31x = 389,482.69
  5. Step 5: Solve for x
    x = 389,482.69/722.31
  6. Step 6: Final answer
    x = 539.22

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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.