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Finding the Fourth Proportional to 386.81, 533.76 and 221.05

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Solution

The fourth proportional to 386.81, 533.76 and 221.05 is: 305.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.81 : 533.76 = 221.05 : x
  2. Step 2: Convert to fraction form
    386.81/533.76 = 221.05/x
  3. Step 3: Cross multiply
    386.81x = 533.76 × 221.05
  4. Step 4: Simplify right side
    386.81x = 117,987.65
  5. Step 5: Solve for x
    x = 117,987.65/386.81
  6. Step 6: Final answer
    x = 305.03

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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.