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Finding the Fourth Proportional to 680.94, 1,021.60 and 218.79

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Solution

The fourth proportional to 680.94, 1,021.60 and 218.79 is: 328.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.94 : 1,021.60 = 218.79 : x
  2. Step 2: Convert to fraction form
    680.94/1,021.60 = 218.79/x
  3. Step 3: Cross multiply
    680.94x = 1,021.60 × 218.79
  4. Step 4: Simplify right side
    680.94x = 223,515.86
  5. Step 5: Solve for x
    x = 223,515.86/680.94
  6. Step 6: Final answer
    x = 328.25

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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.