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Finding the Fourth Proportional to 386.80, 533.78 and 221.02

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Solution

The fourth proportional to 386.80, 533.78 and 221.02 is: 305.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.80 : 533.78 = 221.02 : x
  2. Step 2: Convert to fraction form
    386.80/533.78 = 221.02/x
  3. Step 3: Cross multiply
    386.80x = 533.78 × 221.02
  4. Step 4: Simplify right side
    386.80x = 117,976.06
  5. Step 5: Solve for x
    x = 117,976.06/386.80
  6. Step 6: Final answer
    x = 305.01

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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.