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Finding the Fourth Proportional to 321.40, 443.09 and 210.70

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Solution

The fourth proportional to 321.40, 443.09 and 210.70 is: 290.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.40 : 443.09 = 210.70 : x
  2. Step 2: Convert to fraction form
    321.40/443.09 = 210.70/x
  3. Step 3: Cross multiply
    321.40x = 443.09 × 210.70
  4. Step 4: Simplify right side
    321.40x = 93,357.37
  5. Step 5: Solve for x
    x = 93,357.37/321.40
  6. Step 6: Final answer
    x = 290.48

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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.