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Finding the Fourth Proportional to 369.07, 509.21 and 221.78

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Solution

The fourth proportional to 369.07, 509.21 and 221.78 is: 305.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    369.07 : 509.21 = 221.78 : x
  2. Step 2: Convert to fraction form
    369.07/509.21 = 221.78/x
  3. Step 3: Cross multiply
    369.07x = 509.21 × 221.78
  4. Step 4: Simplify right side
    369.07x = 112,932.59
  5. Step 5: Solve for x
    x = 112,932.59/369.07
  6. Step 6: Final answer
    x = 305.99

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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.