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Finding the Fourth Proportional to 278.30, 383.90 and 161.78

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Solution

The fourth proportional to 278.30, 383.90 and 161.78 is: 223.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.30 : 383.90 = 161.78 : x
  2. Step 2: Convert to fraction form
    278.30/383.90 = 161.78/x
  3. Step 3: Cross multiply
    278.30x = 383.90 × 161.78
  4. Step 4: Simplify right side
    278.30x = 62,107.34
  5. Step 5: Solve for x
    x = 62,107.34/278.30
  6. Step 6: Final answer
    x = 223.17

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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.