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Finding the Fourth Proportional to 855.92, 1,284 and 393.68

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Solution

The fourth proportional to 855.92, 1,284 and 393.68 is: 590.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.92 : 1,284 = 393.68 : x
  2. Step 2: Convert to fraction form
    855.92/1,284 = 393.68/x
  3. Step 3: Cross multiply
    855.92x = 1,284 × 393.68
  4. Step 4: Simplify right side
    855.92x = 505,485.12
  5. Step 5: Solve for x
    x = 505,485.12/855.92
  6. Step 6: Final answer
    x = 590.58

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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.