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Finding the Fourth Proportional to 815.85, 1,223.40 and 238.61

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Solution

The fourth proportional to 815.85, 1,223.40 and 238.61 is: 357.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.85 : 1,223.40 = 238.61 : x
  2. Step 2: Convert to fraction form
    815.85/1,223.40 = 238.61/x
  3. Step 3: Cross multiply
    815.85x = 1,223.40 × 238.61
  4. Step 4: Simplify right side
    815.85x = 291,914.28
  5. Step 5: Solve for x
    x = 291,914.28/815.85
  6. Step 6: Final answer
    x = 357.80

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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.