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Finding the Fourth Proportional to 326.43, 489.30 and 280.64

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Solution

The fourth proportional to 326.43, 489.30 and 280.64 is: 420.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    326.43 : 489.30 = 280.64 : x
  2. Step 2: Convert to fraction form
    326.43/489.30 = 280.64/x
  3. Step 3: Cross multiply
    326.43x = 489.30 × 280.64
  4. Step 4: Simplify right side
    326.43x = 137,317.15
  5. Step 5: Solve for x
    x = 137,317.15/326.43
  6. Step 6: Final answer
    x = 420.66

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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.