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Finding the Fourth Proportional to 284.32, 426.40 and 78.90

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Solution

The fourth proportional to 284.32, 426.40 and 78.90 is: 118.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    284.32 : 426.40 = 78.90 : x
  2. Step 2: Convert to fraction form
    284.32/426.40 = 78.90/x
  3. Step 3: Cross multiply
    284.32x = 426.40 × 78.90
  4. Step 4: Simplify right side
    284.32x = 33,642.96
  5. Step 5: Solve for x
    x = 33,642.96/284.32
  6. Step 6: Final answer
    x = 118.33

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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.