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Finding the Fourth Proportional to 806.21, 1,209.45 and 258.34

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Solution

The fourth proportional to 806.21, 1,209.45 and 258.34 is: 387.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.21 : 1,209.45 = 258.34 : x
  2. Step 2: Convert to fraction form
    806.21/1,209.45 = 258.34/x
  3. Step 3: Cross multiply
    806.21x = 1,209.45 × 258.34
  4. Step 4: Simplify right side
    806.21x = 312,447.26
  5. Step 5: Solve for x
    x = 312,447.26/806.21
  6. Step 6: Final answer
    x = 387.55

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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.