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Finding the Fourth Proportional to 698.45, 1,047.35 and 643.73

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Solution

The fourth proportional to 698.45, 1,047.35 and 643.73 is: 965.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    698.45 : 1,047.35 = 643.73 : x
  2. Step 2: Convert to fraction form
    698.45/1,047.35 = 643.73/x
  3. Step 3: Cross multiply
    698.45x = 1,047.35 × 643.73
  4. Step 4: Simplify right side
    698.45x = 674,202.16
  5. Step 5: Solve for x
    x = 674,202.16/698.45
  6. Step 6: Final answer
    x = 965.29

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.