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Finding the Fourth Proportional to 290.81, 436.26 and 85.41

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Solution

The fourth proportional to 290.81, 436.26 and 85.41 is: 128.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.81 : 436.26 = 85.41 : x
  2. Step 2: Convert to fraction form
    290.81/436.26 = 85.41/x
  3. Step 3: Cross multiply
    290.81x = 436.26 × 85.41
  4. Step 4: Simplify right side
    290.81x = 37,260.97
  5. Step 5: Solve for x
    x = 37,260.97/290.81
  6. Step 6: Final answer
    x = 128.13

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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.