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Finding the Fourth Proportional to 815.66, 1,223.49 and 405.08

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Solution

The fourth proportional to 815.66, 1,223.49 and 405.08 is: 607.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.66 : 1,223.49 = 405.08 : x
  2. Step 2: Convert to fraction form
    815.66/1,223.49 = 405.08/x
  3. Step 3: Cross multiply
    815.66x = 1,223.49 × 405.08
  4. Step 4: Simplify right side
    815.66x = 495,611.33
  5. Step 5: Solve for x
    x = 495,611.33/815.66
  6. Step 6: Final answer
    x = 607.62

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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.