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Finding the Fourth Proportional to 318.93, 439.95 and 208.21

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Solution

The fourth proportional to 318.93, 439.95 and 208.21 is: 287.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.93 : 439.95 = 208.21 : x
  2. Step 2: Convert to fraction form
    318.93/439.95 = 208.21/x
  3. Step 3: Cross multiply
    318.93x = 439.95 × 208.21
  4. Step 4: Simplify right side
    318.93x = 91,601.99
  5. Step 5: Solve for x
    x = 91,601.99/318.93
  6. Step 6: Final answer
    x = 287.22

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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.