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Finding the Fourth Proportional to 1,278.85, 1,919.70 and 662.39

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Solution

The fourth proportional to 1,278.85, 1,919.70 and 662.39 is: 994.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.85 : 1,919.70 = 662.39 : x
  2. Step 2: Convert to fraction form
    1,278.85/1,919.70 = 662.39/x
  3. Step 3: Cross multiply
    1,278.85x = 1,919.70 × 662.39
  4. Step 4: Simplify right side
    1,278.85x = 1,271,581.97
  5. Step 5: Solve for x
    x = 1,271,581.97/1,278.85
  6. Step 6: Final answer
    x = 994.32

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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.