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Finding the Fourth Proportional to 306.36, 422.28 and 189.72

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Solution

The fourth proportional to 306.36, 422.28 and 189.72 is: 261.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.36 : 422.28 = 189.72 : x
  2. Step 2: Convert to fraction form
    306.36/422.28 = 189.72/x
  3. Step 3: Cross multiply
    306.36x = 422.28 × 189.72
  4. Step 4: Simplify right side
    306.36x = 80,114.96
  5. Step 5: Solve for x
    x = 80,114.96/306.36
  6. Step 6: Final answer
    x = 261.51

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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.