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Finding the Fourth Proportional to 309.96, 428.04 and 309.24

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Solution

The fourth proportional to 309.96, 428.04 and 309.24 is: 427.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.96 : 428.04 = 309.24 : x
  2. Step 2: Convert to fraction form
    309.96/428.04 = 309.24/x
  3. Step 3: Cross multiply
    309.96x = 428.04 × 309.24
  4. Step 4: Simplify right side
    309.96x = 132,367.09
  5. Step 5: Solve for x
    x = 132,367.09/309.96
  6. Step 6: Final answer
    x = 427.05

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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.