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Finding the Fourth Proportional to 649.96, 891.12 and 638.30

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Solution

The fourth proportional to 649.96, 891.12 and 638.30 is: 875.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.96 : 891.12 = 638.30 : x
  2. Step 2: Convert to fraction form
    649.96/891.12 = 638.30/x
  3. Step 3: Cross multiply
    649.96x = 891.12 × 638.30
  4. Step 4: Simplify right side
    649.96x = 568,801.90
  5. Step 5: Solve for x
    x = 568,801.90/649.96
  6. Step 6: Final answer
    x = 875.13

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.