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Finding the Fourth Proportional to 299.80, 420.80 and 299.80

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Solution

The fourth proportional to 299.80, 420.80 and 299.80 is: 420.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    299.80 : 420.80 = 299.80 : x
  2. Step 2: Convert to fraction form
    299.80/420.80 = 299.80/x
  3. Step 3: Cross multiply
    299.80x = 420.80 × 299.80
  4. Step 4: Simplify right side
    299.80x = 126,155.84
  5. Step 5: Solve for x
    x = 126,155.84/299.80
  6. Step 6: Final answer
    x = 420.80

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.