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Finding the Fourth Proportional to 218.40, 300.78 and 190.80

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Solution

The fourth proportional to 218.40, 300.78 and 190.80 is: 262.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.40 : 300.78 = 190.80 : x
  2. Step 2: Convert to fraction form
    218.40/300.78 = 190.80/x
  3. Step 3: Cross multiply
    218.40x = 300.78 × 190.80
  4. Step 4: Simplify right side
    218.40x = 57,388.82
  5. Step 5: Solve for x
    x = 57,388.82/218.40
  6. Step 6: Final answer
    x = 262.77

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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.