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Finding the Fourth Proportional to 291.20, 401.64 and 197.80

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Solution

The fourth proportional to 291.20, 401.64 and 197.80 is: 272.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.20 : 401.64 = 197.80 : x
  2. Step 2: Convert to fraction form
    291.20/401.64 = 197.80/x
  3. Step 3: Cross multiply
    291.20x = 401.64 × 197.80
  4. Step 4: Simplify right side
    291.20x = 79,444.39
  5. Step 5: Solve for x
    x = 79,444.39/291.20
  6. Step 6: Final answer
    x = 272.82

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.