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Finding the Fourth Proportional to 918.29, 1,378.64 and 879.20

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Solution

The fourth proportional to 918.29, 1,378.64 and 879.20 is: 1,319.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    918.29 : 1,378.64 = 879.20 : x
  2. Step 2: Convert to fraction form
    918.29/1,378.64 = 879.20/x
  3. Step 3: Cross multiply
    918.29x = 1,378.64 × 879.20
  4. Step 4: Simplify right side
    918.29x = 1,212,100.29
  5. Step 5: Solve for x
    x = 1,212,100.29/918.29
  6. Step 6: Final answer
    x = 1,319.96

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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.