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Finding the Fourth Proportional to 330.40, 455.79 and 281.80

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Solution

The fourth proportional to 330.40, 455.79 and 281.80 is: 388.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    330.40 : 455.79 = 281.80 : x
  2. Step 2: Convert to fraction form
    330.40/455.79 = 281.80/x
  3. Step 3: Cross multiply
    330.40x = 455.79 × 281.80
  4. Step 4: Simplify right side
    330.40x = 128,441.62
  5. Step 5: Solve for x
    x = 128,441.62/330.40
  6. Step 6: Final answer
    x = 388.75

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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.