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Finding the Fourth Proportional to 318.75, 439.69 and 208.28

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Solution

The fourth proportional to 318.75, 439.69 and 208.28 is: 287.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.75 : 439.69 = 208.28 : x
  2. Step 2: Convert to fraction form
    318.75/439.69 = 208.28/x
  3. Step 3: Cross multiply
    318.75x = 439.69 × 208.28
  4. Step 4: Simplify right side
    318.75x = 91,575.39
  5. Step 5: Solve for x
    x = 91,575.39/318.75
  6. Step 6: Final answer
    x = 287.30

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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.