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Finding the Fourth Proportional to 997.02, 1,375.70 and 643.05

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Solution

The fourth proportional to 997.02, 1,375.70 and 643.05 is: 887.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    997.02 : 1,375.70 = 643.05 : x
  2. Step 2: Convert to fraction form
    997.02/1,375.70 = 643.05/x
  3. Step 3: Cross multiply
    997.02x = 1,375.70 × 643.05
  4. Step 4: Simplify right side
    997.02x = 884,640.67
  5. Step 5: Solve for x
    x = 884,640.67/997.02
  6. Step 6: Final answer
    x = 887.28

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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.