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Finding the Fourth Proportional to 872.88, 1,306.80 and 785.40

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Solution

The fourth proportional to 872.88, 1,306.80 and 785.40 is: 1,175.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.88 : 1,306.80 = 785.40 : x
  2. Step 2: Convert to fraction form
    872.88/1,306.80 = 785.40/x
  3. Step 3: Cross multiply
    872.88x = 1,306.80 × 785.40
  4. Step 4: Simplify right side
    872.88x = 1,026,360.72
  5. Step 5: Solve for x
    x = 1,026,360.72/872.88
  6. Step 6: Final answer
    x = 1,175.83

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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.