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Finding the Fourth Proportional to 290.98, 436.42 and 85.51

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Solution

The fourth proportional to 290.98, 436.42 and 85.51 is: 128.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.98 : 436.42 = 85.51 : x
  2. Step 2: Convert to fraction form
    290.98/436.42 = 85.51/x
  3. Step 3: Cross multiply
    290.98x = 436.42 × 85.51
  4. Step 4: Simplify right side
    290.98x = 37,318.27
  5. Step 5: Solve for x
    x = 37,318.27/290.98
  6. Step 6: Final answer
    x = 128.25

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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.