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Finding the Fourth Proportional to 321.15, 480.81 and 259.66

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Solution

The fourth proportional to 321.15, 480.81 and 259.66 is: 388.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.15 : 480.81 = 259.66 : x
  2. Step 2: Convert to fraction form
    321.15/480.81 = 259.66/x
  3. Step 3: Cross multiply
    321.15x = 480.81 × 259.66
  4. Step 4: Simplify right side
    321.15x = 124,847.12
  5. Step 5: Solve for x
    x = 124,847.12/321.15
  6. Step 6: Final answer
    x = 388.75

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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.