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Finding the Fourth Proportional to 680.85, 1,021.43 and 218.66

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Solution

The fourth proportional to 680.85, 1,021.43 and 218.66 is: 328.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.85 : 1,021.43 = 218.66 : x
  2. Step 2: Convert to fraction form
    680.85/1,021.43 = 218.66/x
  3. Step 3: Cross multiply
    680.85x = 1,021.43 × 218.66
  4. Step 4: Simplify right side
    680.85x = 223,345.88
  5. Step 5: Solve for x
    x = 223,345.88/680.85
  6. Step 6: Final answer
    x = 328.04

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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.