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Finding the Fourth Proportional to 890.82, 1,335.69 and 428.58

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Solution

The fourth proportional to 890.82, 1,335.69 and 428.58 is: 642.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.82 : 1,335.69 = 428.58 : x
  2. Step 2: Convert to fraction form
    890.82/1,335.69 = 428.58/x
  3. Step 3: Cross multiply
    890.82x = 1,335.69 × 428.58
  4. Step 4: Simplify right side
    890.82x = 572,450.02
  5. Step 5: Solve for x
    x = 572,450.02/890.82
  6. Step 6: Final answer
    x = 642.61

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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.