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Finding the Fourth Proportional to 643.84, 888.40 and 422.88

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Solution

The fourth proportional to 643.84, 888.40 and 422.88 is: 583.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.84 : 888.40 = 422.88 : x
  2. Step 2: Convert to fraction form
    643.84/888.40 = 422.88/x
  3. Step 3: Cross multiply
    643.84x = 888.40 × 422.88
  4. Step 4: Simplify right side
    643.84x = 375,686.59
  5. Step 5: Solve for x
    x = 375,686.59/643.84
  6. Step 6: Final answer
    x = 583.51

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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.