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Finding the Fourth Proportional to 890.54, 1,228.02 and 643.04

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Solution

The fourth proportional to 890.54, 1,228.02 and 643.04 is: 886.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.54 : 1,228.02 = 643.04 : x
  2. Step 2: Convert to fraction form
    890.54/1,228.02 = 643.04/x
  3. Step 3: Cross multiply
    890.54x = 1,228.02 × 643.04
  4. Step 4: Simplify right side
    890.54x = 789,665.98
  5. Step 5: Solve for x
    x = 789,665.98/890.54
  6. Step 6: Final answer
    x = 886.73

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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.