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Finding the Fourth Proportional to 254.97, 380.69 and 209.21

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Solution

The fourth proportional to 254.97, 380.69 and 209.21 is: 312.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    254.97 : 380.69 = 209.21 : x
  2. Step 2: Convert to fraction form
    254.97/380.69 = 209.21/x
  3. Step 3: Cross multiply
    254.97x = 380.69 × 209.21
  4. Step 4: Simplify right side
    254.97x = 79,641.21
  5. Step 5: Solve for x
    x = 79,641.21/254.97
  6. Step 6: Final answer
    x = 312.36

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.