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Finding the Fourth Proportional to 643.67, 887.91 and 494.69

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Solution

The fourth proportional to 643.67, 887.91 and 494.69 is: 682.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.67 : 887.91 = 494.69 : x
  2. Step 2: Convert to fraction form
    643.67/887.91 = 494.69/x
  3. Step 3: Cross multiply
    643.67x = 887.91 × 494.69
  4. Step 4: Simplify right side
    643.67x = 439,235.76
  5. Step 5: Solve for x
    x = 439,235.76/643.67
  6. Step 6: Final answer
    x = 682.40

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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.