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Finding the Fourth Proportional to 287.96, 396.30 and 261.80

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Solution

The fourth proportional to 287.96, 396.30 and 261.80 is: 360.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.96 : 396.30 = 261.80 : x
  2. Step 2: Convert to fraction form
    287.96/396.30 = 261.80/x
  3. Step 3: Cross multiply
    287.96x = 396.30 × 261.80
  4. Step 4: Simplify right side
    287.96x = 103,749.36
  5. Step 5: Solve for x
    x = 103,749.36/287.96
  6. Step 6: Final answer
    x = 360.30

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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.