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Finding the Fourth Proportional to 1,278.38, 1,763.71 and 780.84

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Solution

The fourth proportional to 1,278.38, 1,763.71 and 780.84 is: 1,077.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.38 : 1,763.71 = 780.84 : x
  2. Step 2: Convert to fraction form
    1,278.38/1,763.71 = 780.84/x
  3. Step 3: Cross multiply
    1,278.38x = 1,763.71 × 780.84
  4. Step 4: Simplify right side
    1,278.38x = 1,377,173.36
  5. Step 5: Solve for x
    x = 1,377,173.36/1,278.38
  6. Step 6: Final answer
    x = 1,077.28

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1.5x scale

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.