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Finding the Fourth Proportional to 268.20, 399.53 and 261.80

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Solution

The fourth proportional to 268.20, 399.53 and 261.80 is: 390.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    268.20 : 399.53 = 261.80 : x
  2. Step 2: Convert to fraction form
    268.20/399.53 = 261.80/x
  3. Step 3: Cross multiply
    268.20x = 399.53 × 261.80
  4. Step 4: Simplify right side
    268.20x = 104,596.95
  5. Step 5: Solve for x
    x = 104,596.95/268.20
  6. Step 6: Final answer
    x = 390.00

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.