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Finding the Fourth Proportional to 1,369.56, 2,055.56 and 639.55

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Solution

The fourth proportional to 1,369.56, 2,055.56 and 639.55 is: 959.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,369.56 : 2,055.56 = 639.55 : x
  2. Step 2: Convert to fraction form
    1,369.56/2,055.56 = 639.55/x
  3. Step 3: Cross multiply
    1,369.56x = 2,055.56 × 639.55
  4. Step 4: Simplify right side
    1,369.56x = 1,314,633.40
  5. Step 5: Solve for x
    x = 1,314,633.40/1,369.56
  6. Step 6: Final answer
    x = 959.89

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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.