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Finding the Fourth Proportional to 838.05, 1,157.61 and 643.96

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Solution

The fourth proportional to 838.05, 1,157.61 and 643.96 is: 889.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.05 : 1,157.61 = 643.96 : x
  2. Step 2: Convert to fraction form
    838.05/1,157.61 = 643.96/x
  3. Step 3: Cross multiply
    838.05x = 1,157.61 × 643.96
  4. Step 4: Simplify right side
    838.05x = 745,454.54
  5. Step 5: Solve for x
    x = 745,454.54/838.05
  6. Step 6: Final answer
    x = 889.51

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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.