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Finding the Fourth Proportional to 326.76, 489.71 and 280.80

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Solution

The fourth proportional to 326.76, 489.71 and 280.80 is: 420.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    326.76 : 489.71 = 280.80 : x
  2. Step 2: Convert to fraction form
    326.76/489.71 = 280.80/x
  3. Step 3: Cross multiply
    326.76x = 489.71 × 280.80
  4. Step 4: Simplify right side
    326.76x = 137,509.94
  5. Step 5: Solve for x
    x = 137,509.94/326.76
  6. Step 6: Final answer
    x = 420.83

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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.