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Finding the Fourth Proportional to 890.49, 1,229.01 and 642.63

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Solution

The fourth proportional to 890.49, 1,229.01 and 642.63 is: 886.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.49 : 1,229.01 = 642.63 : x
  2. Step 2: Convert to fraction form
    890.49/1,229.01 = 642.63/x
  3. Step 3: Cross multiply
    890.49x = 1,229.01 × 642.63
  4. Step 4: Simplify right side
    890.49x = 789,798.70
  5. Step 5: Solve for x
    x = 789,798.70/890.49
  6. Step 6: Final answer
    x = 886.93

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.