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Finding the Fourth Proportional to 927.20, 1,390.80 and 919.10

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Solution

The fourth proportional to 927.20, 1,390.80 and 919.10 is: 1,378.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    927.20 : 1,390.80 = 919.10 : x
  2. Step 2: Convert to fraction form
    927.20/1,390.80 = 919.10/x
  3. Step 3: Cross multiply
    927.20x = 1,390.80 × 919.10
  4. Step 4: Simplify right side
    927.20x = 1,278,284.28
  5. Step 5: Solve for x
    x = 1,278,284.28/927.20
  6. Step 6: Final answer
    x = 1,378.65

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Similar ratio
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1.5x scale

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.