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Finding the Fourth Proportional to 1,369.68, 2,055.89 and 639.77

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Solution

The fourth proportional to 1,369.68, 2,055.89 and 639.77 is: 960.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,369.68 : 2,055.89 = 639.77 : x
  2. Step 2: Convert to fraction form
    1,369.68/2,055.89 = 639.77/x
  3. Step 3: Cross multiply
    1,369.68x = 2,055.89 × 639.77
  4. Step 4: Simplify right side
    1,369.68x = 1,315,296.75
  5. Step 5: Solve for x
    x = 1,315,296.75/1,369.68
  6. Step 6: Final answer
    x = 960.29

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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.