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Finding the Fourth Proportional to 288.64, 398.46 and 221.70

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Solution

The fourth proportional to 288.64, 398.46 and 221.70 is: 306.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.64 : 398.46 = 221.70 : x
  2. Step 2: Convert to fraction form
    288.64/398.46 = 221.70/x
  3. Step 3: Cross multiply
    288.64x = 398.46 × 221.70
  4. Step 4: Simplify right side
    288.64x = 88,338.58
  5. Step 5: Solve for x
    x = 88,338.58/288.64
  6. Step 6: Final answer
    x = 306.05

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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.