Home / 1,280.89-1,767.60-721.35

Finding the Fourth Proportional to 1,280.89, 1,767.60 and 721.35

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Solution

The fourth proportional to 1,280.89, 1,767.60 and 721.35 is: 995.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.89 : 1,767.60 = 721.35 : x
  2. Step 2: Convert to fraction form
    1,280.89/1,767.60 = 721.35/x
  3. Step 3: Cross multiply
    1,280.89x = 1,767.60 × 721.35
  4. Step 4: Simplify right side
    1,280.89x = 1,275,062.68
  5. Step 5: Solve for x
    x = 1,275,062.68/1,280.89
  6. Step 6: Final answer
    x = 995.45

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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.