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Finding the Fourth Proportional to 321.21, 443.20 and 188.40

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Solution

The fourth proportional to 321.21, 443.20 and 188.40 is: 259.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.21 : 443.20 = 188.40 : x
  2. Step 2: Convert to fraction form
    321.21/443.20 = 188.40/x
  3. Step 3: Cross multiply
    321.21x = 443.20 × 188.40
  4. Step 4: Simplify right side
    321.21x = 83,498.88
  5. Step 5: Solve for x
    x = 83,498.88/321.21
  6. Step 6: Final answer
    x = 259.95

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.