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Finding the Fourth Proportional to 813.84, 1,221 and 266.08

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Solution

The fourth proportional to 813.84, 1,221 and 266.08 is: 399.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.84 : 1,221 = 266.08 : x
  2. Step 2: Convert to fraction form
    813.84/1,221 = 266.08/x
  3. Step 3: Cross multiply
    813.84x = 1,221 × 266.08
  4. Step 4: Simplify right side
    813.84x = 324,883.68
  5. Step 5: Solve for x
    x = 324,883.68/813.84
  6. Step 6: Final answer
    x = 399.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.