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Finding the Fourth Proportional to 680.45, 1,020.80 and 247.64

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Solution

The fourth proportional to 680.45, 1,020.80 and 247.64 is: 371.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.45 : 1,020.80 = 247.64 : x
  2. Step 2: Convert to fraction form
    680.45/1,020.80 = 247.64/x
  3. Step 3: Cross multiply
    680.45x = 1,020.80 × 247.64
  4. Step 4: Simplify right side
    680.45x = 252,786.43
  5. Step 5: Solve for x
    x = 252,786.43/680.45
  6. Step 6: Final answer
    x = 371.50

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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.