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Finding the Fourth Proportional to 278.91, 416.58 and 221.20

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Solution

The fourth proportional to 278.91, 416.58 and 221.20 is: 330.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.91 : 416.58 = 221.20 : x
  2. Step 2: Convert to fraction form
    278.91/416.58 = 221.20/x
  3. Step 3: Cross multiply
    278.91x = 416.58 × 221.20
  4. Step 4: Simplify right side
    278.91x = 92,145.63
  5. Step 5: Solve for x
    x = 92,145.63/278.91
  6. Step 6: Final answer
    x = 330.38

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.