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Finding the Fourth Proportional to 378.80, 567.12 and 256.40

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Solution

The fourth proportional to 378.80, 567.12 and 256.40 is: 383.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.80 : 567.12 = 256.40 : x
  2. Step 2: Convert to fraction form
    378.80/567.12 = 256.40/x
  3. Step 3: Cross multiply
    378.80x = 567.12 × 256.40
  4. Step 4: Simplify right side
    378.80x = 145,409.57
  5. Step 5: Solve for x
    x = 145,409.57/378.80
  6. Step 6: Final answer
    x = 383.87

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.