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Finding the Fourth Proportional to 256.68, 353.86 and 221.60

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Solution

The fourth proportional to 256.68, 353.86 and 221.60 is: 305.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.68 : 353.86 = 221.60 : x
  2. Step 2: Convert to fraction form
    256.68/353.86 = 221.60/x
  3. Step 3: Cross multiply
    256.68x = 353.86 × 221.60
  4. Step 4: Simplify right side
    256.68x = 78,415.38
  5. Step 5: Solve for x
    x = 78,415.38/256.68
  6. Step 6: Final answer
    x = 305.50

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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.