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Finding the Fourth Proportional to 312.40, 432.89 and 305.22

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Solution

The fourth proportional to 312.40, 432.89 and 305.22 is: 422.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.40 : 432.89 = 305.22 : x
  2. Step 2: Convert to fraction form
    312.40/432.89 = 305.22/x
  3. Step 3: Cross multiply
    312.40x = 432.89 × 305.22
  4. Step 4: Simplify right side
    312.40x = 132,125.16
  5. Step 5: Solve for x
    x = 132,125.16/312.40
  6. Step 6: Final answer
    x = 422.94

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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.