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Finding the Fourth Proportional to 680.83, 1,021.30 and 212.31

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Solution

The fourth proportional to 680.83, 1,021.30 and 212.31 is: 318.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.83 : 1,021.30 = 212.31 : x
  2. Step 2: Convert to fraction form
    680.83/1,021.30 = 212.31/x
  3. Step 3: Cross multiply
    680.83x = 1,021.30 × 212.31
  4. Step 4: Simplify right side
    680.83x = 216,827.63
  5. Step 5: Solve for x
    x = 216,827.63/680.83
  6. Step 6: Final answer
    x = 318.48

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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.