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Finding the Fourth Proportional to 486.21, 728.80 and 212.22

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Solution

The fourth proportional to 486.21, 728.80 and 212.22 is: 318.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.21 : 728.80 = 212.22 : x
  2. Step 2: Convert to fraction form
    486.21/728.80 = 212.22/x
  3. Step 3: Cross multiply
    486.21x = 728.80 × 212.22
  4. Step 4: Simplify right side
    486.21x = 154,668.14
  5. Step 5: Solve for x
    x = 154,668.14/486.21
  6. Step 6: Final answer
    x = 318.11

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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.