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Finding the Fourth Proportional to 1,369.74, 2,051.73 and 639.90

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Solution

The fourth proportional to 1,369.74, 2,051.73 and 639.90 is: 958.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,369.74 : 2,051.73 = 639.90 : x
  2. Step 2: Convert to fraction form
    1,369.74/2,051.73 = 639.90/x
  3. Step 3: Cross multiply
    1,369.74x = 2,051.73 × 639.90
  4. Step 4: Simplify right side
    1,369.74x = 1,312,902.03
  5. Step 5: Solve for x
    x = 1,312,902.03/1,369.74
  6. Step 6: Final answer
    x = 958.50

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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.