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Finding the Fourth Proportional to 284.21, 393.86 and 278.75

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Solution

The fourth proportional to 284.21, 393.86 and 278.75 is: 386.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    284.21 : 393.86 = 278.75 : x
  2. Step 2: Convert to fraction form
    284.21/393.86 = 278.75/x
  3. Step 3: Cross multiply
    284.21x = 393.86 × 278.75
  4. Step 4: Simplify right side
    284.21x = 109,786.16
  5. Step 5: Solve for x
    x = 109,786.16/284.21
  6. Step 6: Final answer
    x = 386.28

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.