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Finding the Fourth Proportional to 290.89, 436.47 and 128.55

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Solution

The fourth proportional to 290.89, 436.47 and 128.55 is: 192.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.89 : 436.47 = 128.55 : x
  2. Step 2: Convert to fraction form
    290.89/436.47 = 128.55/x
  3. Step 3: Cross multiply
    290.89x = 436.47 × 128.55
  4. Step 4: Simplify right side
    290.89x = 56,107.58
  5. Step 5: Solve for x
    x = 56,107.58/290.89
  6. Step 6: Final answer
    x = 192.89

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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.