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Finding the Fourth Proportional to 1,381.32, 2,070.27 and 640.49

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Solution

The fourth proportional to 1,381.32, 2,070.27 and 640.49 is: 959.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,381.32 : 2,070.27 = 640.49 : x
  2. Step 2: Convert to fraction form
    1,381.32/2,070.27 = 640.49/x
  3. Step 3: Cross multiply
    1,381.32x = 2,070.27 × 640.49
  4. Step 4: Simplify right side
    1,381.32x = 1,325,976.88
  5. Step 5: Solve for x
    x = 1,325,976.88/1,381.32
  6. Step 6: Final answer
    x = 959.93

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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.