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Finding the Fourth Proportional to 266.71, 399.45 and 221.15

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Solution

The fourth proportional to 266.71, 399.45 and 221.15 is: 331.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    266.71 : 399.45 = 221.15 : x
  2. Step 2: Convert to fraction form
    266.71/399.45 = 221.15/x
  3. Step 3: Cross multiply
    266.71x = 399.45 × 221.15
  4. Step 4: Simplify right side
    266.71x = 88,336.70
  5. Step 5: Solve for x
    x = 88,336.70/266.71
  6. Step 6: Final answer
    x = 331.21

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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.