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Finding the Fourth Proportional to 2,121, 3,180.88 and 640.16

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Solution

The fourth proportional to 2,121, 3,180.88 and 640.16 is: 960.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,121 : 3,180.88 = 640.16 : x
  2. Step 2: Convert to fraction form
    2,121/3,180.88 = 640.16/x
  3. Step 3: Cross multiply
    2,121x = 3,180.88 × 640.16
  4. Step 4: Simplify right side
    2,121x = 2,036,272.14
  5. Step 5: Solve for x
    x = 2,036,272.14/2,121
  6. Step 6: Final answer
    x = 960.05

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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.