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Finding the Fourth Proportional to 668.63, 1,003.31 and 278.90

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Solution

The fourth proportional to 668.63, 1,003.31 and 278.90 is: 418.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.63 : 1,003.31 = 278.90 : x
  2. Step 2: Convert to fraction form
    668.63/1,003.31 = 278.90/x
  3. Step 3: Cross multiply
    668.63x = 1,003.31 × 278.90
  4. Step 4: Simplify right side
    668.63x = 279,821.76
  5. Step 5: Solve for x
    x = 279,821.76/668.63
  6. Step 6: Final answer
    x = 418.50

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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.