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Finding the Fourth Proportional to 997.75, 1,376.48 and 643.62

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Solution

The fourth proportional to 997.75, 1,376.48 and 643.62 is: 887.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    997.75 : 1,376.48 = 643.62 : x
  2. Step 2: Convert to fraction form
    997.75/1,376.48 = 643.62/x
  3. Step 3: Cross multiply
    997.75x = 1,376.48 × 643.62
  4. Step 4: Simplify right side
    997.75x = 885,931.67
  5. Step 5: Solve for x
    x = 885,931.67/997.75
  6. Step 6: Final answer
    x = 887.93

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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.