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Finding the Fourth Proportional to 309.48, 427.08 and 221.12

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Solution

The fourth proportional to 309.48, 427.08 and 221.12 is: 305.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.48 : 427.08 = 221.12 : x
  2. Step 2: Convert to fraction form
    309.48/427.08 = 221.12/x
  3. Step 3: Cross multiply
    309.48x = 427.08 × 221.12
  4. Step 4: Simplify right side
    309.48x = 94,433.79
  5. Step 5: Solve for x
    x = 94,433.79/309.48
  6. Step 6: Final answer
    x = 305.14

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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.