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Finding the Fourth Proportional to 290.74, 436.34 and 128.54

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Solution

The fourth proportional to 290.74, 436.34 and 128.54 is: 192.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.74 : 436.34 = 128.54 : x
  2. Step 2: Convert to fraction form
    290.74/436.34 = 128.54/x
  3. Step 3: Cross multiply
    290.74x = 436.34 × 128.54
  4. Step 4: Simplify right side
    290.74x = 56,085.38
  5. Step 5: Solve for x
    x = 56,085.38/290.74
  6. Step 6: Final answer
    x = 192.91

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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.