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Finding the Fourth Proportional to 319.40, 440.43 and 221.21

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Solution

The fourth proportional to 319.40, 440.43 and 221.21 is: 305.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.40 : 440.43 = 221.21 : x
  2. Step 2: Convert to fraction form
    319.40/440.43 = 221.21/x
  3. Step 3: Cross multiply
    319.40x = 440.43 × 221.21
  4. Step 4: Simplify right side
    319.40x = 97,427.52
  5. Step 5: Solve for x
    x = 97,427.52/319.40
  6. Step 6: Final answer
    x = 305.03

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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.