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Finding the Fourth Proportional to 387.96, 578.95 and 378.78

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Solution

The fourth proportional to 387.96, 578.95 and 378.78 is: 565.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.96 : 578.95 = 378.78 : x
  2. Step 2: Convert to fraction form
    387.96/578.95 = 378.78/x
  3. Step 3: Cross multiply
    387.96x = 578.95 × 378.78
  4. Step 4: Simplify right side
    387.96x = 219,291.56
  5. Step 5: Solve for x
    x = 219,291.56/387.96
  6. Step 6: Final answer
    x = 565.24

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.