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Finding the Fourth Proportional to 318.90, 440.13 and 208.31

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Solution

The fourth proportional to 318.90, 440.13 and 208.31 is: 287.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.90 : 440.13 = 208.31 : x
  2. Step 2: Convert to fraction form
    318.90/440.13 = 208.31/x
  3. Step 3: Cross multiply
    318.90x = 440.13 × 208.31
  4. Step 4: Simplify right side
    318.90x = 91,682.06
  5. Step 5: Solve for x
    x = 91,682.06/318.90
  6. Step 6: Final answer
    x = 287.49

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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.