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Finding the Fourth Proportional to 815.67, 1,223.19 and 328.55

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Solution

The fourth proportional to 815.67, 1,223.19 and 328.55 is: 492.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.67 : 1,223.19 = 328.55 : x
  2. Step 2: Convert to fraction form
    815.67/1,223.19 = 328.55/x
  3. Step 3: Cross multiply
    815.67x = 1,223.19 × 328.55
  4. Step 4: Simplify right side
    815.67x = 401,872.96
  5. Step 5: Solve for x
    x = 401,872.96/815.67
  6. Step 6: Final answer
    x = 492.69

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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.