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Finding the Fourth Proportional to 378.16, 521.91 and 315.90

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Solution

The fourth proportional to 378.16, 521.91 and 315.90 is: 435.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.16 : 521.91 = 315.90 : x
  2. Step 2: Convert to fraction form
    378.16/521.91 = 315.90/x
  3. Step 3: Cross multiply
    378.16x = 521.91 × 315.90
  4. Step 4: Simplify right side
    378.16x = 164,871.37
  5. Step 5: Solve for x
    x = 164,871.37/378.16
  6. Step 6: Final answer
    x = 435.99

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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.