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Finding the Fourth Proportional to 640.80, 884.16 and 407.76

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Solution

The fourth proportional to 640.80, 884.16 and 407.76 is: 562.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.80 : 884.16 = 407.76 : x
  2. Step 2: Convert to fraction form
    640.80/884.16 = 407.76/x
  3. Step 3: Cross multiply
    640.80x = 884.16 × 407.76
  4. Step 4: Simplify right side
    640.80x = 360,525.08
  5. Step 5: Solve for x
    x = 360,525.08/640.80
  6. Step 6: Final answer
    x = 562.62

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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.