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Finding the Fourth Proportional to 310.40, 428.06 and 199.68

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Solution

The fourth proportional to 310.40, 428.06 and 199.68 is: 275.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.40 : 428.06 = 199.68 : x
  2. Step 2: Convert to fraction form
    310.40/428.06 = 199.68/x
  3. Step 3: Cross multiply
    310.40x = 428.06 × 199.68
  4. Step 4: Simplify right side
    310.40x = 85,475.02
  5. Step 5: Solve for x
    x = 85,475.02/310.40
  6. Step 6: Final answer
    x = 275.37

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.