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Finding the Fourth Proportional to 790.21, 1,185.38 and 205.21

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Solution

The fourth proportional to 790.21, 1,185.38 and 205.21 is: 307.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    790.21 : 1,185.38 = 205.21 : x
  2. Step 2: Convert to fraction form
    790.21/1,185.38 = 205.21/x
  3. Step 3: Cross multiply
    790.21x = 1,185.38 × 205.21
  4. Step 4: Simplify right side
    790.21x = 243,245.90
  5. Step 5: Solve for x
    x = 243,245.90/790.21
  6. Step 6: Final answer
    x = 307.83

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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.