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Finding the Fourth Proportional to 309.75, 427.36 and 221.25

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Solution

The fourth proportional to 309.75, 427.36 and 221.25 is: 305.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.75 : 427.36 = 221.25 : x
  2. Step 2: Convert to fraction form
    309.75/427.36 = 221.25/x
  3. Step 3: Cross multiply
    309.75x = 427.36 × 221.25
  4. Step 4: Simplify right side
    309.75x = 94,553.40
  5. Step 5: Solve for x
    x = 94,553.40/309.75
  6. Step 6: Final answer
    x = 305.26

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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.