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Finding the Fourth Proportional to 386.88, 533.90 and 221.12

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Solution

The fourth proportional to 386.88, 533.90 and 221.12 is: 305.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.88 : 533.90 = 221.12 : x
  2. Step 2: Convert to fraction form
    386.88/533.90 = 221.12/x
  3. Step 3: Cross multiply
    386.88x = 533.90 × 221.12
  4. Step 4: Simplify right side
    386.88x = 118,055.97
  5. Step 5: Solve for x
    x = 118,055.97/386.88
  6. Step 6: Final answer
    x = 305.15

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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.