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Finding the Fourth Proportional to 457.42, 685.80 and 213.80

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Solution

The fourth proportional to 457.42, 685.80 and 213.80 is: 320.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    457.42 : 685.80 = 213.80 : x
  2. Step 2: Convert to fraction form
    457.42/685.80 = 213.80/x
  3. Step 3: Cross multiply
    457.42x = 685.80 × 213.80
  4. Step 4: Simplify right side
    457.42x = 146,624.04
  5. Step 5: Solve for x
    x = 146,624.04/457.42
  6. Step 6: Final answer
    x = 320.55

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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.