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Finding the Fourth Proportional to 386.01, 579.21 and 212.81

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Solution

The fourth proportional to 386.01, 579.21 and 212.81 is: 319.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.01 : 579.21 = 212.81 : x
  2. Step 2: Convert to fraction form
    386.01/579.21 = 212.81/x
  3. Step 3: Cross multiply
    386.01x = 579.21 × 212.81
  4. Step 4: Simplify right side
    386.01x = 123,261.68
  5. Step 5: Solve for x
    x = 123,261.68/386.01
  6. Step 6: Final answer
    x = 319.32

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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.