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Finding the Fourth Proportional to 278.81, 385.26 and 216.80

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Solution

The fourth proportional to 278.81, 385.26 and 216.80 is: 299.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.81 : 385.26 = 216.80 : x
  2. Step 2: Convert to fraction form
    278.81/385.26 = 216.80/x
  3. Step 3: Cross multiply
    278.81x = 385.26 × 216.80
  4. Step 4: Simplify right side
    278.81x = 83,524.37
  5. Step 5: Solve for x
    x = 83,524.37/278.81
  6. Step 6: Final answer
    x = 299.57

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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.