Home / 1,247.40-1,720.70-749.78

Finding the Fourth Proportional to 1,247.40, 1,720.70 and 749.78

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Solution

The fourth proportional to 1,247.40, 1,720.70 and 749.78 is: 1,034.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,247.40 : 1,720.70 = 749.78 : x
  2. Step 2: Convert to fraction form
    1,247.40/1,720.70 = 749.78/x
  3. Step 3: Cross multiply
    1,247.40x = 1,720.70 × 749.78
  4. Step 4: Simplify right side
    1,247.40x = 1,290,146.45
  5. Step 5: Solve for x
    x = 1,290,146.45/1,247.40
  6. Step 6: Final answer
    x = 1,034.27

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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.