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Finding the Fourth Proportional to 890.59, 1,336.74 and 428.68

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Solution

The fourth proportional to 890.59, 1,336.74 and 428.68 is: 643.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.59 : 1,336.74 = 428.68 : x
  2. Step 2: Convert to fraction form
    890.59/1,336.74 = 428.68/x
  3. Step 3: Cross multiply
    890.59x = 1,336.74 × 428.68
  4. Step 4: Simplify right side
    890.59x = 573,031.56
  5. Step 5: Solve for x
    x = 573,031.56/890.59
  6. Step 6: Final answer
    x = 643.43

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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.