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Finding the Fourth Proportional to 890.08, 1,335.99 and 428.18

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Solution

The fourth proportional to 890.08, 1,335.99 and 428.18 is: 642.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.08 : 1,335.99 = 428.18 : x
  2. Step 2: Convert to fraction form
    890.08/1,335.99 = 428.18/x
  3. Step 3: Cross multiply
    890.08x = 1,335.99 × 428.18
  4. Step 4: Simplify right side
    890.08x = 572,042.06
  5. Step 5: Solve for x
    x = 572,042.06/890.08
  6. Step 6: Final answer
    x = 642.68

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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.