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Finding the Fourth Proportional to 248.56, 342.78 and 221.20

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Solution

The fourth proportional to 248.56, 342.78 and 221.20 is: 305.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    248.56 : 342.78 = 221.20 : x
  2. Step 2: Convert to fraction form
    248.56/342.78 = 221.20/x
  3. Step 3: Cross multiply
    248.56x = 342.78 × 221.20
  4. Step 4: Simplify right side
    248.56x = 75,822.94
  5. Step 5: Solve for x
    x = 75,822.94/248.56
  6. Step 6: Final answer
    x = 305.05

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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.