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Finding the Fourth Proportional to 280.68, 421.47 and 211.28

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Solution

The fourth proportional to 280.68, 421.47 and 211.28 is: 317.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.68 : 421.47 = 211.28 : x
  2. Step 2: Convert to fraction form
    280.68/421.47 = 211.28/x
  3. Step 3: Cross multiply
    280.68x = 421.47 × 211.28
  4. Step 4: Simplify right side
    280.68x = 89,046.07
  5. Step 5: Solve for x
    x = 89,046.07/280.68
  6. Step 6: Final answer
    x = 317.26

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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.