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Finding the Fourth Proportional to 291.49, 401.76 and 212.80

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Solution

The fourth proportional to 291.49, 401.76 and 212.80 is: 293.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.49 : 401.76 = 212.80 : x
  2. Step 2: Convert to fraction form
    291.49/401.76 = 212.80/x
  3. Step 3: Cross multiply
    291.49x = 401.76 × 212.80
  4. Step 4: Simplify right side
    291.49x = 85,494.53
  5. Step 5: Solve for x
    x = 85,494.53/291.49
  6. Step 6: Final answer
    x = 293.30

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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.