Home / 1,287.90-1,931.85-422.28

Finding the Fourth Proportional to 1,287.90, 1,931.85 and 422.28

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Solution

The fourth proportional to 1,287.90, 1,931.85 and 422.28 is: 633.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.90 : 1,931.85 = 422.28 : x
  2. Step 2: Convert to fraction form
    1,287.90/1,931.85 = 422.28/x
  3. Step 3: Cross multiply
    1,287.90x = 1,931.85 × 422.28
  4. Step 4: Simplify right side
    1,287.90x = 815,781.62
  5. Step 5: Solve for x
    x = 815,781.62/1,287.90
  6. Step 6: Final answer
    x = 633.42

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.