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Finding the Fourth Proportional to 287.96, 396.98 and 221.68

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Solution

The fourth proportional to 287.96, 396.98 and 221.68 is: 305.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.96 : 396.98 = 221.68 : x
  2. Step 2: Convert to fraction form
    287.96/396.98 = 221.68/x
  3. Step 3: Cross multiply
    287.96x = 396.98 × 221.68
  4. Step 4: Simplify right side
    287.96x = 88,002.53
  5. Step 5: Solve for x
    x = 88,002.53/287.96
  6. Step 6: Final answer
    x = 305.61

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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.