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Finding the Fourth Proportional to 386.81, 533.79 and 221.02

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Solution

The fourth proportional to 386.81, 533.79 and 221.02 is: 305.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.81 : 533.79 = 221.02 : x
  2. Step 2: Convert to fraction form
    386.81/533.79 = 221.02/x
  3. Step 3: Cross multiply
    386.81x = 533.79 × 221.02
  4. Step 4: Simplify right side
    386.81x = 117,978.27
  5. Step 5: Solve for x
    x = 117,978.27/386.81
  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.