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Finding the Fourth Proportional to 310.59, 428.40 and 212.22

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Solution

The fourth proportional to 310.59, 428.40 and 212.22 is: 292.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.59 : 428.40 = 212.22 : x
  2. Step 2: Convert to fraction form
    310.59/428.40 = 212.22/x
  3. Step 3: Cross multiply
    310.59x = 428.40 × 212.22
  4. Step 4: Simplify right side
    310.59x = 90,915.05
  5. Step 5: Solve for x
    x = 90,915.05/310.59
  6. Step 6: Final answer
    x = 292.72

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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.