Home / 1,272.40-1,906.80-621.70

Finding the Fourth Proportional to 1,272.40, 1,906.80 and 621.70

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Solution

The fourth proportional to 1,272.40, 1,906.80 and 621.70 is: 931.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,272.40 : 1,906.80 = 621.70 : x
  2. Step 2: Convert to fraction form
    1,272.40/1,906.80 = 621.70/x
  3. Step 3: Cross multiply
    1,272.40x = 1,906.80 × 621.70
  4. Step 4: Simplify right side
    1,272.40x = 1,185,457.56
  5. Step 5: Solve for x
    x = 1,185,457.56/1,272.40
  6. Step 6: Final answer
    x = 931.67

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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.