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Finding the Fourth Proportional to 291.40, 436.74 and 128.92

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Solution

The fourth proportional to 291.40, 436.74 and 128.92 is: 193.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.40 : 436.74 = 128.92 : x
  2. Step 2: Convert to fraction form
    291.40/436.74 = 128.92/x
  3. Step 3: Cross multiply
    291.40x = 436.74 × 128.92
  4. Step 4: Simplify right side
    291.40x = 56,304.52
  5. Step 5: Solve for x
    x = 56,304.52/291.40
  6. Step 6: Final answer
    x = 193.22

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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.