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Finding the Fourth Proportional to 290.40, 402.72 and 261.60

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Solution

The fourth proportional to 290.40, 402.72 and 261.60 is: 362.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.40 : 402.72 = 261.60 : x
  2. Step 2: Convert to fraction form
    290.40/402.72 = 261.60/x
  3. Step 3: Cross multiply
    290.40x = 402.72 × 261.60
  4. Step 4: Simplify right side
    290.40x = 105,351.55
  5. Step 5: Solve for x
    x = 105,351.55/290.40
  6. Step 6: Final answer
    x = 362.78

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.