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Finding the Fourth Proportional to 1,333.30, 2,000.40 and 640.40

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Solution

The fourth proportional to 1,333.30, 2,000.40 and 640.40 is: 960.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,333.30 : 2,000.40 = 640.40 : x
  2. Step 2: Convert to fraction form
    1,333.30/2,000.40 = 640.40/x
  3. Step 3: Cross multiply
    1,333.30x = 2,000.40 × 640.40
  4. Step 4: Simplify right side
    1,333.30x = 1,281,056.16
  5. Step 5: Solve for x
    x = 1,281,056.16/1,333.30
  6. Step 6: Final answer
    x = 960.82

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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.