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Finding the Fourth Proportional to 818.68, 1,225.90 and 643.82

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Solution

The fourth proportional to 818.68, 1,225.90 and 643.82 is: 964.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.68 : 1,225.90 = 643.82 : x
  2. Step 2: Convert to fraction form
    818.68/1,225.90 = 643.82/x
  3. Step 3: Cross multiply
    818.68x = 1,225.90 × 643.82
  4. Step 4: Simplify right side
    818.68x = 789,258.94
  5. Step 5: Solve for x
    x = 789,258.94/818.68
  6. Step 6: Final answer
    x = 964.06

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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.