Home / 1,385.19-1,911.80-787.73

Finding the Fourth Proportional to 1,385.19, 1,911.80 and 787.73

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Solution

The fourth proportional to 1,385.19, 1,911.80 and 787.73 is: 1,087.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,385.19 : 1,911.80 = 787.73 : x
  2. Step 2: Convert to fraction form
    1,385.19/1,911.80 = 787.73/x
  3. Step 3: Cross multiply
    1,385.19x = 1,911.80 × 787.73
  4. Step 4: Simplify right side
    1,385.19x = 1,505,974.62
  5. Step 5: Solve for x
    x = 1,505,974.62/1,385.19
  6. Step 6: Final answer
    x = 1,087.20

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Double scale
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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.