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Finding the Fourth Proportional to 668.90, 1,003.19 and 206.68

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Solution

The fourth proportional to 668.90, 1,003.19 and 206.68 is: 309.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.90 : 1,003.19 = 206.68 : x
  2. Step 2: Convert to fraction form
    668.90/1,003.19 = 206.68/x
  3. Step 3: Cross multiply
    668.90x = 1,003.19 × 206.68
  4. Step 4: Simplify right side
    668.90x = 207,334.83
  5. Step 5: Solve for x
    x = 207,334.83/668.90
  6. Step 6: Final answer
    x = 309.97

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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.