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Finding the Fourth Proportional to 278.78, 384.80 and 195.90

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Solution

The fourth proportional to 278.78, 384.80 and 195.90 is: 270.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.78 : 384.80 = 195.90 : x
  2. Step 2: Convert to fraction form
    278.78/384.80 = 195.90/x
  3. Step 3: Cross multiply
    278.78x = 384.80 × 195.90
  4. Step 4: Simplify right side
    278.78x = 75,381.34
  5. Step 5: Solve for x
    x = 75,381.34/278.78
  6. Step 6: Final answer
    x = 270.40

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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.