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Finding the Fourth Proportional to 643.77, 966.90 and 551.43

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Solution

The fourth proportional to 643.77, 966.90 and 551.43 is: 828.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.77 : 966.90 = 551.43 : x
  2. Step 2: Convert to fraction form
    643.77/966.90 = 551.43/x
  3. Step 3: Cross multiply
    643.77x = 966.90 × 551.43
  4. Step 4: Simplify right side
    643.77x = 533,177.67
  5. Step 5: Solve for x
    x = 533,177.67/643.77
  6. Step 6: Final answer
    x = 828.21

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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.