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Finding the Fourth Proportional to 386.85, 533.86 and 221.06

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Solution

The fourth proportional to 386.85, 533.86 and 221.06 is: 305.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.85 : 533.86 = 221.06 : x
  2. Step 2: Convert to fraction form
    386.85/533.86 = 221.06/x
  3. Step 3: Cross multiply
    386.85x = 533.86 × 221.06
  4. Step 4: Simplify right side
    386.85x = 118,015.09
  5. Step 5: Solve for x
    x = 118,015.09/386.85
  6. Step 6: Final answer
    x = 305.07

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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.