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Finding the Fourth Proportional to 698.31, 963.79 and 399.58

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Solution

The fourth proportional to 698.31, 963.79 and 399.58 is: 551.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    698.31 : 963.79 = 399.58 : x
  2. Step 2: Convert to fraction form
    698.31/963.79 = 399.58/x
  3. Step 3: Cross multiply
    698.31x = 963.79 × 399.58
  4. Step 4: Simplify right side
    698.31x = 385,107.80
  5. Step 5: Solve for x
    x = 385,107.80/698.31
  6. Step 6: Final answer
    x = 551.49

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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.