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Finding the Fourth Proportional to 319.56, 440.64 and 221.28

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Solution

The fourth proportional to 319.56, 440.64 and 221.28 is: 305.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.56 : 440.64 = 221.28 : x
  2. Step 2: Convert to fraction form
    319.56/440.64 = 221.28/x
  3. Step 3: Cross multiply
    319.56x = 440.64 × 221.28
  4. Step 4: Simplify right side
    319.56x = 97,504.82
  5. Step 5: Solve for x
    x = 97,504.82/319.56
  6. Step 6: Final answer
    x = 305.12

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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.