Home / 1,370.27-1,890.78-780.68

Finding the Fourth Proportional to 1,370.27, 1,890.78 and 780.68

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Solution

The fourth proportional to 1,370.27, 1,890.78 and 780.68 is: 1,077.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,370.27 : 1,890.78 = 780.68 : x
  2. Step 2: Convert to fraction form
    1,370.27/1,890.78 = 780.68/x
  3. Step 3: Cross multiply
    1,370.27x = 1,890.78 × 780.68
  4. Step 4: Simplify right side
    1,370.27x = 1,476,094.13
  5. Step 5: Solve for x
    x = 1,476,094.13/1,370.27
  6. Step 6: Final answer
    x = 1,077.23

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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.