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Finding the Fourth Proportional to 872.31, 1,307.85 and 790.30

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Solution

The fourth proportional to 872.31, 1,307.85 and 790.30 is: 1,184.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.31 : 1,307.85 = 790.30 : x
  2. Step 2: Convert to fraction form
    872.31/1,307.85 = 790.30/x
  3. Step 3: Cross multiply
    872.31x = 1,307.85 × 790.30
  4. Step 4: Simplify right side
    872.31x = 1,033,593.86
  5. Step 5: Solve for x
    x = 1,033,593.86/872.31
  6. Step 6: Final answer
    x = 1,184.89

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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.