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Finding the Fourth Proportional to 290.75, 436.08 and 128.39

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Solution

The fourth proportional to 290.75, 436.08 and 128.39 is: 192.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.75 : 436.08 = 128.39 : x
  2. Step 2: Convert to fraction form
    290.75/436.08 = 128.39/x
  3. Step 3: Cross multiply
    290.75x = 436.08 × 128.39
  4. Step 4: Simplify right side
    290.75x = 55,988.52
  5. Step 5: Solve for x
    x = 55,988.52/290.75
  6. Step 6: Final answer
    x = 192.57

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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.