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Finding the Fourth Proportional to 639.38, 881.80 and 515

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Solution

The fourth proportional to 639.38, 881.80 and 515 is: 710.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.38 : 881.80 = 515 : x
  2. Step 2: Convert to fraction form
    639.38/881.80 = 515/x
  3. Step 3: Cross multiply
    639.38x = 881.80 × 515
  4. Step 4: Simplify right side
    639.38x = 454,127
  5. Step 5: Solve for x
    x = 454,127/639.38
  6. Step 6: Final answer
    x = 710.26

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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.