Home / 1,278.20-1,761.80-904.70

Finding the Fourth Proportional to 1,278.20, 1,761.80 and 904.70

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Solution

The fourth proportional to 1,278.20, 1,761.80 and 904.70 is: 1,246.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.20 : 1,761.80 = 904.70 : x
  2. Step 2: Convert to fraction form
    1,278.20/1,761.80 = 904.70/x
  3. Step 3: Cross multiply
    1,278.20x = 1,761.80 × 904.70
  4. Step 4: Simplify right side
    1,278.20x = 1,593,900.34
  5. Step 5: Solve for x
    x = 1,593,900.34/1,278.20
  6. Step 6: Final answer
    x = 1,246.99

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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.