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Finding the Fourth Proportional to 312.84, 428.85 and 297.18

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Solution

The fourth proportional to 312.84, 428.85 and 297.18 is: 407.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.84 : 428.85 = 297.18 : x
  2. Step 2: Convert to fraction form
    312.84/428.85 = 297.18/x
  3. Step 3: Cross multiply
    312.84x = 428.85 × 297.18
  4. Step 4: Simplify right side
    312.84x = 127,445.64
  5. Step 5: Solve for x
    x = 127,445.64/312.84
  6. Step 6: Final answer
    x = 407.38

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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.