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Finding the Fourth Proportional to 280.99, 387.96 and 211.21

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Solution

The fourth proportional to 280.99, 387.96 and 211.21 is: 291.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.99 : 387.96 = 211.21 : x
  2. Step 2: Convert to fraction form
    280.99/387.96 = 211.21/x
  3. Step 3: Cross multiply
    280.99x = 387.96 × 211.21
  4. Step 4: Simplify right side
    280.99x = 81,941.05
  5. Step 5: Solve for x
    x = 81,941.05/280.99
  6. Step 6: Final answer
    x = 291.61

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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.