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Finding the Fourth Proportional to 805.98, 1,209.21 and 258.15

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Solution

The fourth proportional to 805.98, 1,209.21 and 258.15 is: 387.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.98 : 1,209.21 = 258.15 : x
  2. Step 2: Convert to fraction form
    805.98/1,209.21 = 258.15/x
  3. Step 3: Cross multiply
    805.98x = 1,209.21 × 258.15
  4. Step 4: Simplify right side
    805.98x = 312,156.27
  5. Step 5: Solve for x
    x = 312,156.27/805.98
  6. Step 6: Final answer
    x = 387.30

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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.