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Finding the Fourth Proportional to 459.12, 691.23 and 315.78

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Solution

The fourth proportional to 459.12, 691.23 and 315.78 is: 475.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    459.12 : 691.23 = 315.78 : x
  2. Step 2: Convert to fraction form
    459.12/691.23 = 315.78/x
  3. Step 3: Cross multiply
    459.12x = 691.23 × 315.78
  4. Step 4: Simplify right side
    459.12x = 218,276.61
  5. Step 5: Solve for x
    x = 218,276.61/459.12
  6. Step 6: Final answer
    x = 475.42

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.