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Finding the Fourth Proportional to 818.28, 1,226.58 and 428.08

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Solution

The fourth proportional to 818.28, 1,226.58 and 428.08 is: 641.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.28 : 1,226.58 = 428.08 : x
  2. Step 2: Convert to fraction form
    818.28/1,226.58 = 428.08/x
  3. Step 3: Cross multiply
    818.28x = 1,226.58 × 428.08
  4. Step 4: Simplify right side
    818.28x = 525,074.37
  5. Step 5: Solve for x
    x = 525,074.37/818.28
  6. Step 6: Final answer
    x = 641.68

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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.