Home / 1,218.89-1,681.85-721.55

Finding the Fourth Proportional to 1,218.89, 1,681.85 and 721.55

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Solution

The fourth proportional to 1,218.89, 1,681.85 and 721.55 is: 995.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,218.89 : 1,681.85 = 721.55 : x
  2. Step 2: Convert to fraction form
    1,218.89/1,681.85 = 721.55/x
  3. Step 3: Cross multiply
    1,218.89x = 1,681.85 × 721.55
  4. Step 4: Simplify right side
    1,218.89x = 1,213,538.87
  5. Step 5: Solve for x
    x = 1,213,538.87/1,218.89
  6. Step 6: Final answer
    x = 995.61

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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.