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Finding the Fourth Proportional to 551.42, 760.67 and 420.20

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Solution

The fourth proportional to 551.42, 760.67 and 420.20 is: 579.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    551.42 : 760.67 = 420.20 : x
  2. Step 2: Convert to fraction form
    551.42/760.67 = 420.20/x
  3. Step 3: Cross multiply
    551.42x = 760.67 × 420.20
  4. Step 4: Simplify right side
    551.42x = 319,633.53
  5. Step 5: Solve for x
    x = 319,633.53/551.42
  6. Step 6: Final answer
    x = 579.66

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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.