Home / 1,421.12-2,131.45-728.30

Finding the Fourth Proportional to 1,421.12, 2,131.45 and 728.30

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Solution

The fourth proportional to 1,421.12, 2,131.45 and 728.30 is: 1,092.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.12 : 2,131.45 = 728.30 : x
  2. Step 2: Convert to fraction form
    1,421.12/2,131.45 = 728.30/x
  3. Step 3: Cross multiply
    1,421.12x = 2,131.45 × 728.30
  4. Step 4: Simplify right side
    1,421.12x = 1,552,335.04
  5. Step 5: Solve for x
    x = 1,552,335.04/1,421.12
  6. Step 6: Final answer
    x = 1,092.33

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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.