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Finding the Fourth Proportional to 320.78, 480.85 and 205.35

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Solution

The fourth proportional to 320.78, 480.85 and 205.35 is: 307.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.78 : 480.85 = 205.35 : x
  2. Step 2: Convert to fraction form
    320.78/480.85 = 205.35/x
  3. Step 3: Cross multiply
    320.78x = 480.85 × 205.35
  4. Step 4: Simplify right side
    320.78x = 98,742.55
  5. Step 5: Solve for x
    x = 98,742.55/320.78
  6. Step 6: Final answer
    x = 307.82

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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.