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Finding the Fourth Proportional to 643.79, 889.44 and 422.66

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Solution

The fourth proportional to 643.79, 889.44 and 422.66 is: 583.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.79 : 889.44 = 422.66 : x
  2. Step 2: Convert to fraction form
    643.79/889.44 = 422.66/x
  3. Step 3: Cross multiply
    643.79x = 889.44 × 422.66
  4. Step 4: Simplify right side
    643.79x = 375,930.71
  5. Step 5: Solve for x
    x = 375,930.71/643.79
  6. Step 6: Final answer
    x = 583.93

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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.