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Finding the Fourth Proportional to 306.68, 422.30 and 287.11

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Solution

The fourth proportional to 306.68, 422.30 and 287.11 is: 395.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.68 : 422.30 = 287.11 : x
  2. Step 2: Convert to fraction form
    306.68/422.30 = 287.11/x
  3. Step 3: Cross multiply
    306.68x = 422.30 × 287.11
  4. Step 4: Simplify right side
    306.68x = 121,243.01
  5. Step 5: Solve for x
    x = 121,243.01/306.68
  6. Step 6: Final answer
    x = 395.34

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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.