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Finding the Fourth Proportional to 890.64, 1,336.09 and 428.33

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Solution

The fourth proportional to 890.64, 1,336.09 and 428.33 is: 642.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.64 : 1,336.09 = 428.33 : x
  2. Step 2: Convert to fraction form
    890.64/1,336.09 = 428.33/x
  3. Step 3: Cross multiply
    890.64x = 1,336.09 × 428.33
  4. Step 4: Simplify right side
    890.64x = 572,287.43
  5. Step 5: Solve for x
    x = 572,287.43/890.64
  6. Step 6: Final answer
    x = 642.56

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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.