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Finding the Fourth Proportional to 320.58, 442.47 and 209.85

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Solution

The fourth proportional to 320.58, 442.47 and 209.85 is: 289.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.58 : 442.47 = 209.85 : x
  2. Step 2: Convert to fraction form
    320.58/442.47 = 209.85/x
  3. Step 3: Cross multiply
    320.58x = 442.47 × 209.85
  4. Step 4: Simplify right side
    320.58x = 92,852.33
  5. Step 5: Solve for x
    x = 92,852.33/320.58
  6. Step 6: Final answer
    x = 289.64

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.