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Finding the Fourth Proportional to 813.94, 1,220 and 326.42

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Solution

The fourth proportional to 813.94, 1,220 and 326.42 is: 489.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.94 : 1,220 = 326.42 : x
  2. Step 2: Convert to fraction form
    813.94/1,220 = 326.42/x
  3. Step 3: Cross multiply
    813.94x = 1,220 × 326.42
  4. Step 4: Simplify right side
    813.94x = 398,232.40
  5. Step 5: Solve for x
    x = 398,232.40/813.94
  6. Step 6: Final answer
    x = 489.27

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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.