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Finding the Fourth Proportional to 938.49, 1,295.34 and 643.89

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Solution

The fourth proportional to 938.49, 1,295.34 and 643.89 is: 888.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.49 : 1,295.34 = 643.89 : x
  2. Step 2: Convert to fraction form
    938.49/1,295.34 = 643.89/x
  3. Step 3: Cross multiply
    938.49x = 1,295.34 × 643.89
  4. Step 4: Simplify right side
    938.49x = 834,056.47
  5. Step 5: Solve for x
    x = 834,056.47/938.49
  6. Step 6: Final answer
    x = 888.72

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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.