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Finding the Fourth Proportional to 303.72, 419.40 and 221.28

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Solution

The fourth proportional to 303.72, 419.40 and 221.28 is: 305.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    303.72 : 419.40 = 221.28 : x
  2. Step 2: Convert to fraction form
    303.72/419.40 = 221.28/x
  3. Step 3: Cross multiply
    303.72x = 419.40 × 221.28
  4. Step 4: Simplify right side
    303.72x = 92,804.83
  5. Step 5: Solve for x
    x = 92,804.83/303.72
  6. Step 6: Final answer
    x = 305.56

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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.