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Finding the Fourth Proportional to 290.87, 436.24 and 85.38

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Solution

The fourth proportional to 290.87, 436.24 and 85.38 is: 128.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.87 : 436.24 = 85.38 : x
  2. Step 2: Convert to fraction form
    290.87/436.24 = 85.38/x
  3. Step 3: Cross multiply
    290.87x = 436.24 × 85.38
  4. Step 4: Simplify right side
    290.87x = 37,246.17
  5. Step 5: Solve for x
    x = 37,246.17/290.87
  6. Step 6: Final answer
    x = 128.05

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.