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Finding the Fourth Proportional to 920.50, 1,272.70 and 879.70

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Solution

The fourth proportional to 920.50, 1,272.70 and 879.70 is: 1,216.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.50 : 1,272.70 = 879.70 : x
  2. Step 2: Convert to fraction form
    920.50/1,272.70 = 879.70/x
  3. Step 3: Cross multiply
    920.50x = 1,272.70 × 879.70
  4. Step 4: Simplify right side
    920.50x = 1,119,594.19
  5. Step 5: Solve for x
    x = 1,119,594.19/920.50
  6. Step 6: Final answer
    x = 1,216.29

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.