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Finding the Fourth Proportional to 643.31, 891.49 and 631.00

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Solution

The fourth proportional to 643.31, 891.49 and 631.00 is: 874.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.31 : 891.49 = 631.00 : x
  2. Step 2: Convert to fraction form
    643.31/891.49 = 631.00/x
  3. Step 3: Cross multiply
    643.31x = 891.49 × 631.00
  4. Step 4: Simplify right side
    643.31x = 562,525.73
  5. Step 5: Solve for x
    x = 562,525.73/643.31
  6. Step 6: Final answer
    x = 874.43

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.