Home / 1,421.30-1,961.35-861.68

Finding the Fourth Proportional to 1,421.30, 1,961.35 and 861.68

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Solution

The fourth proportional to 1,421.30, 1,961.35 and 861.68 is: 1,189.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.30 : 1,961.35 = 861.68 : x
  2. Step 2: Convert to fraction form
    1,421.30/1,961.35 = 861.68/x
  3. Step 3: Cross multiply
    1,421.30x = 1,961.35 × 861.68
  4. Step 4: Simplify right side
    1,421.30x = 1,690,058.82
  5. Step 5: Solve for x
    x = 1,690,058.82/1,421.30
  6. Step 6: Final answer
    x = 1,189.09

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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.