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Finding the Fourth Proportional to 640.86, 961.29 and 208.08

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Solution

The fourth proportional to 640.86, 961.29 and 208.08 is: 312.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.86 : 961.29 = 208.08 : x
  2. Step 2: Convert to fraction form
    640.86/961.29 = 208.08/x
  3. Step 3: Cross multiply
    640.86x = 961.29 × 208.08
  4. Step 4: Simplify right side
    640.86x = 200,025.22
  5. Step 5: Solve for x
    x = 200,025.22/640.86
  6. Step 6: Final answer
    x = 312.12

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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.