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Finding the Fourth Proportional to 639.06, 881.61 and 402.84

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Solution

The fourth proportional to 639.06, 881.61 and 402.84 is: 555.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.06 : 881.61 = 402.84 : x
  2. Step 2: Convert to fraction form
    639.06/881.61 = 402.84/x
  3. Step 3: Cross multiply
    639.06x = 881.61 × 402.84
  4. Step 4: Simplify right side
    639.06x = 355,147.39
  5. Step 5: Solve for x
    x = 355,147.39/639.06
  6. Step 6: Final answer
    x = 555.74

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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.