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Finding the Fourth Proportional to 256.40, 353.04 and 216.80

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Solution

The fourth proportional to 256.40, 353.04 and 216.80 is: 298.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.40 : 353.04 = 216.80 : x
  2. Step 2: Convert to fraction form
    256.40/353.04 = 216.80/x
  3. Step 3: Cross multiply
    256.40x = 353.04 × 216.80
  4. Step 4: Simplify right side
    256.40x = 76,539.07
  5. Step 5: Solve for x
    x = 76,539.07/256.40
  6. Step 6: Final answer
    x = 298.51

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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.