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Finding the Fourth Proportional to 212.69, 319.08 and 68.40

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Solution

The fourth proportional to 212.69, 319.08 and 68.40 is: 102.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.69 : 319.08 = 68.40 : x
  2. Step 2: Convert to fraction form
    212.69/319.08 = 68.40/x
  3. Step 3: Cross multiply
    212.69x = 319.08 × 68.40
  4. Step 4: Simplify right side
    212.69x = 21,825.07
  5. Step 5: Solve for x
    x = 21,825.07/212.69
  6. Step 6: Final answer
    x = 102.62

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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.