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Finding the Fourth Proportional to 231.40, 345.09 and 221.80

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Solution

The fourth proportional to 231.40, 345.09 and 221.80 is: 330.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.40 : 345.09 = 221.80 : x
  2. Step 2: Convert to fraction form
    231.40/345.09 = 221.80/x
  3. Step 3: Cross multiply
    231.40x = 345.09 × 221.80
  4. Step 4: Simplify right side
    231.40x = 76,540.96
  5. Step 5: Solve for x
    x = 76,540.96/231.40
  6. Step 6: Final answer
    x = 330.77

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.