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Finding the Fourth Proportional to 306.60, 422.15 and 278.90

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Solution

The fourth proportional to 306.60, 422.15 and 278.90 is: 384.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.60 : 422.15 = 278.90 : x
  2. Step 2: Convert to fraction form
    306.60/422.15 = 278.90/x
  3. Step 3: Cross multiply
    306.60x = 422.15 × 278.90
  4. Step 4: Simplify right side
    306.60x = 117,737.64
  5. Step 5: Solve for x
    x = 117,737.64/306.60
  6. Step 6: Final answer
    x = 384.01

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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.