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Finding the Fourth Proportional to 290.88, 401.42 and 172.80

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Solution

The fourth proportional to 290.88, 401.42 and 172.80 is: 238.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.88 : 401.42 = 172.80 : x
  2. Step 2: Convert to fraction form
    290.88/401.42 = 172.80/x
  3. Step 3: Cross multiply
    290.88x = 401.42 × 172.80
  4. Step 4: Simplify right side
    290.88x = 69,365.38
  5. Step 5: Solve for x
    x = 69,365.38/290.88
  6. Step 6: Final answer
    x = 238.47

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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.