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Finding the Fourth Proportional to 280.75, 421.19 and 109.75

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Solution

The fourth proportional to 280.75, 421.19 and 109.75 is: 164.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.75 : 421.19 = 109.75 : x
  2. Step 2: Convert to fraction form
    280.75/421.19 = 109.75/x
  3. Step 3: Cross multiply
    280.75x = 421.19 × 109.75
  4. Step 4: Simplify right side
    280.75x = 46,225.60
  5. Step 5: Solve for x
    x = 46,225.60/280.75
  6. Step 6: Final answer
    x = 164.65

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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.