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Finding the Fourth Proportional to 312.80, 434.64 and 308.92

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Solution

The fourth proportional to 312.80, 434.64 and 308.92 is: 429.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.80 : 434.64 = 308.92 : x
  2. Step 2: Convert to fraction form
    312.80/434.64 = 308.92/x
  3. Step 3: Cross multiply
    312.80x = 434.64 × 308.92
  4. Step 4: Simplify right side
    312.80x = 134,268.99
  5. Step 5: Solve for x
    x = 134,268.99/312.80
  6. Step 6: Final answer
    x = 429.25

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.