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Finding the Fourth Proportional to 698.75, 1,048.08 and 287.78

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Solution

The fourth proportional to 698.75, 1,048.08 and 287.78 is: 431.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    698.75 : 1,048.08 = 287.78 : x
  2. Step 2: Convert to fraction form
    698.75/1,048.08 = 287.78/x
  3. Step 3: Cross multiply
    698.75x = 1,048.08 × 287.78
  4. Step 4: Simplify right side
    698.75x = 301,616.46
  5. Step 5: Solve for x
    x = 301,616.46/698.75
  6. Step 6: Final answer
    x = 431.65

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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.