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Finding the Fourth Proportional to 212.68, 319.38 and 208.72

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Solution

The fourth proportional to 212.68, 319.38 and 208.72 is: 313.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.68 : 319.38 = 208.72 : x
  2. Step 2: Convert to fraction form
    212.68/319.38 = 208.72/x
  3. Step 3: Cross multiply
    212.68x = 319.38 × 208.72
  4. Step 4: Simplify right side
    212.68x = 66,660.99
  5. Step 5: Solve for x
    x = 66,660.99/212.68
  6. Step 6: Final answer
    x = 313.43

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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.