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Finding the Fourth Proportional to 309.51, 424.28 and 308.90

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Solution

The fourth proportional to 309.51, 424.28 and 308.90 is: 423.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.51 : 424.28 = 308.90 : x
  2. Step 2: Convert to fraction form
    309.51/424.28 = 308.90/x
  3. Step 3: Cross multiply
    309.51x = 424.28 × 308.90
  4. Step 4: Simplify right side
    309.51x = 131,056.43
  5. Step 5: Solve for x
    x = 131,056.43/309.51
  6. Step 6: Final answer
    x = 423.43

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.