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Finding the Fourth Proportional to 845.10, 1,268.22 and 639.90

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Solution

The fourth proportional to 845.10, 1,268.22 and 639.90 is: 960.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    845.10 : 1,268.22 = 639.90 : x
  2. Step 2: Convert to fraction form
    845.10/1,268.22 = 639.90/x
  3. Step 3: Cross multiply
    845.10x = 1,268.22 × 639.90
  4. Step 4: Simplify right side
    845.10x = 811,533.98
  5. Step 5: Solve for x
    x = 811,533.98/845.10
  6. Step 6: Final answer
    x = 960.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.