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Finding the Fourth Proportional to 356.12, 491.40 and 208.80

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Solution

The fourth proportional to 356.12, 491.40 and 208.80 is: 288.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    356.12 : 491.40 = 208.80 : x
  2. Step 2: Convert to fraction form
    356.12/491.40 = 208.80/x
  3. Step 3: Cross multiply
    356.12x = 491.40 × 208.80
  4. Step 4: Simplify right side
    356.12x = 102,604.32
  5. Step 5: Solve for x
    x = 102,604.32/356.12
  6. Step 6: Final answer
    x = 288.12

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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.