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Finding the Fourth Proportional to 321.43, 443.65 and 311.18

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Solution

The fourth proportional to 321.43, 443.65 and 311.18 is: 429.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.43 : 443.65 = 311.18 : x
  2. Step 2: Convert to fraction form
    321.43/443.65 = 311.18/x
  3. Step 3: Cross multiply
    321.43x = 443.65 × 311.18
  4. Step 4: Simplify right side
    321.43x = 138,055.01
  5. Step 5: Solve for x
    x = 138,055.01/321.43
  6. Step 6: Final answer
    x = 429.50

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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.