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Finding the Fourth Proportional to 278.36, 381.86 and 261.80

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Solution

The fourth proportional to 278.36, 381.86 and 261.80 is: 359.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.36 : 381.86 = 261.80 : x
  2. Step 2: Convert to fraction form
    278.36/381.86 = 261.80/x
  3. Step 3: Cross multiply
    278.36x = 381.86 × 261.80
  4. Step 4: Simplify right side
    278.36x = 99,970.95
  5. Step 5: Solve for x
    x = 99,970.95/278.36
  6. Step 6: Final answer
    x = 359.14

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.