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Finding the Fourth Proportional to 838.72, 1,255.80 and 790.20

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Solution

The fourth proportional to 838.72, 1,255.80 and 790.20 is: 1,183.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.72 : 1,255.80 = 790.20 : x
  2. Step 2: Convert to fraction form
    838.72/1,255.80 = 790.20/x
  3. Step 3: Cross multiply
    838.72x = 1,255.80 × 790.20
  4. Step 4: Simplify right side
    838.72x = 992,333.16
  5. Step 5: Solve for x
    x = 992,333.16/838.72
  6. Step 6: Final answer
    x = 1,183.15

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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.