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Finding the Fourth Proportional to 291.29, 436.55 and 128.61

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Solution

The fourth proportional to 291.29, 436.55 and 128.61 is: 192.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.29 : 436.55 = 128.61 : x
  2. Step 2: Convert to fraction form
    291.29/436.55 = 128.61/x
  3. Step 3: Cross multiply
    291.29x = 436.55 × 128.61
  4. Step 4: Simplify right side
    291.29x = 56,144.05
  5. Step 5: Solve for x
    x = 56,144.05/291.29
  6. Step 6: Final answer
    x = 192.75

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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.