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Finding the Fourth Proportional to 386.61, 533.29 and 220.78

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Solution

The fourth proportional to 386.61, 533.29 and 220.78 is: 304.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.61 : 533.29 = 220.78 : x
  2. Step 2: Convert to fraction form
    386.61/533.29 = 220.78/x
  3. Step 3: Cross multiply
    386.61x = 533.29 × 220.78
  4. Step 4: Simplify right side
    386.61x = 117,739.77
  5. Step 5: Solve for x
    x = 117,739.77/386.61
  6. Step 6: Final answer
    x = 304.54

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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.