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Finding the Fourth Proportional to 786.88, 1,180.40 and 209.80

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Solution

The fourth proportional to 786.88, 1,180.40 and 209.80 is: 314.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.88 : 1,180.40 = 209.80 : x
  2. Step 2: Convert to fraction form
    786.88/1,180.40 = 209.80/x
  3. Step 3: Cross multiply
    786.88x = 1,180.40 × 209.80
  4. Step 4: Simplify right side
    786.88x = 247,647.92
  5. Step 5: Solve for x
    x = 247,647.92/786.88
  6. Step 6: Final answer
    x = 314.72

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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.