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Finding the Fourth Proportional to 304.68, 420.21 and 221.76

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Solution

The fourth proportional to 304.68, 420.21 and 221.76 is: 305.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    304.68 : 420.21 = 221.76 : x
  2. Step 2: Convert to fraction form
    304.68/420.21 = 221.76/x
  3. Step 3: Cross multiply
    304.68x = 420.21 × 221.76
  4. Step 4: Simplify right side
    304.68x = 93,185.77
  5. Step 5: Solve for x
    x = 93,185.77/304.68
  6. Step 6: Final answer
    x = 305.85

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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.