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Finding the Fourth Proportional to 280.91, 421.64 and 208.55

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Solution

The fourth proportional to 280.91, 421.64 and 208.55 is: 313.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.91 : 421.64 = 208.55 : x
  2. Step 2: Convert to fraction form
    280.91/421.64 = 208.55/x
  3. Step 3: Cross multiply
    280.91x = 421.64 × 208.55
  4. Step 4: Simplify right side
    280.91x = 87,933.02
  5. Step 5: Solve for x
    x = 87,933.02/280.91
  6. Step 6: Final answer
    x = 313.03

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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.