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Finding the Fourth Proportional to 278.74, 418.64 and 142.05

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Solution

The fourth proportional to 278.74, 418.64 and 142.05 is: 213.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.74 : 418.64 = 142.05 : x
  2. Step 2: Convert to fraction form
    278.74/418.64 = 142.05/x
  3. Step 3: Cross multiply
    278.74x = 418.64 × 142.05
  4. Step 4: Simplify right side
    278.74x = 59,468.67
  5. Step 5: Solve for x
    x = 59,468.67/278.74
  6. Step 6: Final answer
    x = 213.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.