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Finding the Fourth Proportional to 313.42, 428.81 and 312.22

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Solution

The fourth proportional to 313.42, 428.81 and 312.22 is: 427.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    313.42 : 428.81 = 312.22 : x
  2. Step 2: Convert to fraction form
    313.42/428.81 = 312.22/x
  3. Step 3: Cross multiply
    313.42x = 428.81 × 312.22
  4. Step 4: Simplify right side
    313.42x = 133,883.06
  5. Step 5: Solve for x
    x = 133,883.06/313.42
  6. Step 6: Final answer
    x = 427.17

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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.