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Finding the Fourth Proportional to 291.42, 402.18 and 221.30

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Solution

The fourth proportional to 291.42, 402.18 and 221.30 is: 305.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.42 : 402.18 = 221.30 : x
  2. Step 2: Convert to fraction form
    291.42/402.18 = 221.30/x
  3. Step 3: Cross multiply
    291.42x = 402.18 × 221.30
  4. Step 4: Simplify right side
    291.42x = 89,002.43
  5. Step 5: Solve for x
    x = 89,002.43/291.42
  6. Step 6: Final answer
    x = 305.41

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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.