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Finding the Fourth Proportional to 290.40, 400.75 and 172.38

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Solution

The fourth proportional to 290.40, 400.75 and 172.38 is: 237.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.40 : 400.75 = 172.38 : x
  2. Step 2: Convert to fraction form
    290.40/400.75 = 172.38/x
  3. Step 3: Cross multiply
    290.40x = 400.75 × 172.38
  4. Step 4: Simplify right side
    290.40x = 69,081.29
  5. Step 5: Solve for x
    x = 69,081.29/290.40
  6. Step 6: Final answer
    x = 237.88

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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.