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Finding the Fourth Proportional to 290.45, 400.75 and 172.40

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Solution

The fourth proportional to 290.45, 400.75 and 172.40 is: 237.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.45 : 400.75 = 172.40 : x
  2. Step 2: Convert to fraction form
    290.45/400.75 = 172.40/x
  3. Step 3: Cross multiply
    290.45x = 400.75 × 172.40
  4. Step 4: Simplify right side
    290.45x = 69,086.87
  5. Step 5: Solve for x
    x = 69,086.87/290.45
  6. Step 6: Final answer
    x = 237.86

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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.