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Finding the Fourth Proportional to 308.21, 424.67 and 209.79

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Solution

The fourth proportional to 308.21, 424.67 and 209.79 is: 289.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    308.21 : 424.67 = 209.79 : x
  2. Step 2: Convert to fraction form
    308.21/424.67 = 209.79/x
  3. Step 3: Cross multiply
    308.21x = 424.67 × 209.79
  4. Step 4: Simplify right side
    308.21x = 89,090.47
  5. Step 5: Solve for x
    x = 89,090.47/308.21
  6. Step 6: Final answer
    x = 289.06

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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.