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Finding the Fourth Proportional to 800.13, 1,100.31 and 640.77

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Solution

The fourth proportional to 800.13, 1,100.31 and 640.77 is: 881.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    800.13 : 1,100.31 = 640.77 : x
  2. Step 2: Convert to fraction form
    800.13/1,100.31 = 640.77/x
  3. Step 3: Cross multiply
    800.13x = 1,100.31 × 640.77
  4. Step 4: Simplify right side
    800.13x = 705,045.64
  5. Step 5: Solve for x
    x = 705,045.64/800.13
  6. Step 6: Final answer
    x = 881.16

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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.