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Finding the Fourth Proportional to 290.90, 401.45 and 172.87

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Solution

The fourth proportional to 290.90, 401.45 and 172.87 is: 238.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.90 : 401.45 = 172.87 : x
  2. Step 2: Convert to fraction form
    290.90/401.45 = 172.87/x
  3. Step 3: Cross multiply
    290.90x = 401.45 × 172.87
  4. Step 4: Simplify right side
    290.90x = 69,396.79
  5. Step 5: Solve for x
    x = 69,396.79/290.90
  6. Step 6: Final answer
    x = 238.56

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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.