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Finding the Fourth Proportional to 798.90, 1,198.28 and 278.70

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Solution

The fourth proportional to 798.90, 1,198.28 and 278.70 is: 418.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    798.90 : 1,198.28 = 278.70 : x
  2. Step 2: Convert to fraction form
    798.90/1,198.28 = 278.70/x
  3. Step 3: Cross multiply
    798.90x = 1,198.28 × 278.70
  4. Step 4: Simplify right side
    798.90x = 333,960.64
  5. Step 5: Solve for x
    x = 333,960.64/798.90
  6. Step 6: Final answer
    x = 418.03

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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.