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Finding the Fourth Proportional to 698.40, 1,047.96 and 287.88

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Solution

The fourth proportional to 698.40, 1,047.96 and 287.88 is: 431.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    698.40 : 1,047.96 = 287.88 : x
  2. Step 2: Convert to fraction form
    698.40/1,047.96 = 287.88/x
  3. Step 3: Cross multiply
    698.40x = 1,047.96 × 287.88
  4. Step 4: Simplify right side
    698.40x = 301,686.72
  5. Step 5: Solve for x
    x = 301,686.72/698.40
  6. Step 6: Final answer
    x = 431.97

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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.