Home / 1,231.40-1,698.91-789.55

Finding the Fourth Proportional to 1,231.40, 1,698.91 and 789.55

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Solution

The fourth proportional to 1,231.40, 1,698.91 and 789.55 is: 1,089.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,231.40 : 1,698.91 = 789.55 : x
  2. Step 2: Convert to fraction form
    1,231.40/1,698.91 = 789.55/x
  3. Step 3: Cross multiply
    1,231.40x = 1,698.91 × 789.55
  4. Step 4: Simplify right side
    1,231.40x = 1,341,374.39
  5. Step 5: Solve for x
    x = 1,341,374.39/1,231.40
  6. Step 6: Final answer
    x = 1,089.31

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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.