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Finding the Fourth Proportional to 290.78, 401.25 and 159.78

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Solution

The fourth proportional to 290.78, 401.25 and 159.78 is: 220.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.78 : 401.25 = 159.78 : x
  2. Step 2: Convert to fraction form
    290.78/401.25 = 159.78/x
  3. Step 3: Cross multiply
    290.78x = 401.25 × 159.78
  4. Step 4: Simplify right side
    290.78x = 64,111.73
  5. Step 5: Solve for x
    x = 64,111.73/290.78
  6. Step 6: Final answer
    x = 220.48

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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.