Home / 1,421.25-1,961.16-831.78

Finding the Fourth Proportional to 1,421.25, 1,961.16 and 831.78

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Solution

The fourth proportional to 1,421.25, 1,961.16 and 831.78 is: 1,147.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.25 : 1,961.16 = 831.78 : x
  2. Step 2: Convert to fraction form
    1,421.25/1,961.16 = 831.78/x
  3. Step 3: Cross multiply
    1,421.25x = 1,961.16 × 831.78
  4. Step 4: Simplify right side
    1,421.25x = 1,631,253.66
  5. Step 5: Solve for x
    x = 1,631,253.66/1,421.25
  6. Step 6: Final answer
    x = 1,147.76

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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.