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Finding the Fourth Proportional to 310.40, 428 and 212.22

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Solution

The fourth proportional to 310.40, 428 and 212.22 is: 292.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.40 : 428 = 212.22 : x
  2. Step 2: Convert to fraction form
    310.40/428 = 212.22/x
  3. Step 3: Cross multiply
    310.40x = 428 × 212.22
  4. Step 4: Simplify right side
    310.40x = 90,830.16
  5. Step 5: Solve for x
    x = 90,830.16/310.40
  6. Step 6: Final answer
    x = 292.62

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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.