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Finding the Fourth Proportional to 281.28, 388.80 and 215.76

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Solution

The fourth proportional to 281.28, 388.80 and 215.76 is: 298.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.28 : 388.80 = 215.76 : x
  2. Step 2: Convert to fraction form
    281.28/388.80 = 215.76/x
  3. Step 3: Cross multiply
    281.28x = 388.80 × 215.76
  4. Step 4: Simplify right side
    281.28x = 83,887.49
  5. Step 5: Solve for x
    x = 83,887.49/281.28
  6. Step 6: Final answer
    x = 298.23

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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.