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Finding the Fourth Proportional to 911, 1,372.71 and 811.54

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Solution

The fourth proportional to 911, 1,372.71 and 811.54 is: 1,222.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    911 : 1,372.71 = 811.54 : x
  2. Step 2: Convert to fraction form
    911/1,372.71 = 811.54/x
  3. Step 3: Cross multiply
    911x = 1,372.71 × 811.54
  4. Step 4: Simplify right side
    911x = 1,114,010.48
  5. Step 5: Solve for x
    x = 1,114,010.48/911
  6. Step 6: Final answer
    x = 1,222.84

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.