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Finding the Fourth Proportional to 319.38, 440.78 and 209.18

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Solution

The fourth proportional to 319.38, 440.78 and 209.18 is: 288.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.38 : 440.78 = 209.18 : x
  2. Step 2: Convert to fraction form
    319.38/440.78 = 209.18/x
  3. Step 3: Cross multiply
    319.38x = 440.78 × 209.18
  4. Step 4: Simplify right side
    319.38x = 92,200.16
  5. Step 5: Solve for x
    x = 92,200.16/319.38
  6. Step 6: Final answer
    x = 288.68

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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.