Home / 1,421.19-1,961.28-831.74

Finding the Fourth Proportional to 1,421.19, 1,961.28 and 831.74

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Solution

The fourth proportional to 1,421.19, 1,961.28 and 831.74 is: 1,147.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.19 : 1,961.28 = 831.74 : x
  2. Step 2: Convert to fraction form
    1,421.19/1,961.28 = 831.74/x
  3. Step 3: Cross multiply
    1,421.19x = 1,961.28 × 831.74
  4. Step 4: Simplify right side
    1,421.19x = 1,631,265.22
  5. Step 5: Solve for x
    x = 1,631,265.22/1,421.19
  6. Step 6: Final answer
    x = 1,147.82

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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.