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Finding the Fourth Proportional to 305.50, 422.39 and 291.90

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Solution

The fourth proportional to 305.50, 422.39 and 291.90 is: 403.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.50 : 422.39 = 291.90 : x
  2. Step 2: Convert to fraction form
    305.50/422.39 = 291.90/x
  3. Step 3: Cross multiply
    305.50x = 422.39 × 291.90
  4. Step 4: Simplify right side
    305.50x = 123,295.64
  5. Step 5: Solve for x
    x = 123,295.64/305.50
  6. Step 6: Final answer
    x = 403.59

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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.