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Finding the Fourth Proportional to 640.89, 884.40 and 408

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Solution

The fourth proportional to 640.89, 884.40 and 408 is: 563.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.89 : 884.40 = 408 : x
  2. Step 2: Convert to fraction form
    640.89/884.40 = 408/x
  3. Step 3: Cross multiply
    640.89x = 884.40 × 408
  4. Step 4: Simplify right side
    640.89x = 360,835.20
  5. Step 5: Solve for x
    x = 360,835.20/640.89
  6. Step 6: Final answer
    x = 563.02

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.