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Finding the Fourth Proportional to 386.88, 533.81 and 221.05

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Solution

The fourth proportional to 386.88, 533.81 and 221.05 is: 305.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.88 : 533.81 = 221.05 : x
  2. Step 2: Convert to fraction form
    386.88/533.81 = 221.05/x
  3. Step 3: Cross multiply
    386.88x = 533.81 × 221.05
  4. Step 4: Simplify right side
    386.88x = 117,998.70
  5. Step 5: Solve for x
    x = 117,998.70/386.88
  6. Step 6: Final answer
    x = 305.00

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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.