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Finding the Fourth Proportional to 378.12, 521.42 and 315.93

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Solution

The fourth proportional to 378.12, 521.42 and 315.93 is: 435.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.12 : 521.42 = 315.93 : x
  2. Step 2: Convert to fraction form
    378.12/521.42 = 315.93/x
  3. Step 3: Cross multiply
    378.12x = 521.42 × 315.93
  4. Step 4: Simplify right side
    378.12x = 164,732.22
  5. Step 5: Solve for x
    x = 164,732.22/378.12
  6. Step 6: Final answer
    x = 435.66

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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.