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Finding the Fourth Proportional to 1,208.79, 1,813.41 and 428.94

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Solution

The fourth proportional to 1,208.79, 1,813.41 and 428.94 is: 643.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,208.79 : 1,813.41 = 428.94 : x
  2. Step 2: Convert to fraction form
    1,208.79/1,813.41 = 428.94/x
  3. Step 3: Cross multiply
    1,208.79x = 1,813.41 × 428.94
  4. Step 4: Simplify right side
    1,208.79x = 777,844.09
  5. Step 5: Solve for x
    x = 777,844.09/1,208.79
  6. Step 6: Final answer
    x = 643.49

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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.