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Finding the Fourth Proportional to 319.91, 440.78 and 221.49

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Solution

The fourth proportional to 319.91, 440.78 and 221.49 is: 305.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.91 : 440.78 = 221.49 : x
  2. Step 2: Convert to fraction form
    319.91/440.78 = 221.49/x
  3. Step 3: Cross multiply
    319.91x = 440.78 × 221.49
  4. Step 4: Simplify right side
    319.91x = 97,627.25
  5. Step 5: Solve for x
    x = 97,627.25/319.91
  6. Step 6: Final answer
    x = 305.18

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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.