Home / 1,419.90-2,128.07-639.08

Finding the Fourth Proportional to 1,419.90, 2,128.07 and 639.08

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Solution

The fourth proportional to 1,419.90, 2,128.07 and 639.08 is: 957.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,419.90 : 2,128.07 = 639.08 : x
  2. Step 2: Convert to fraction form
    1,419.90/2,128.07 = 639.08/x
  3. Step 3: Cross multiply
    1,419.90x = 2,128.07 × 639.08
  4. Step 4: Simplify right side
    1,419.90x = 1,359,993.14
  5. Step 5: Solve for x
    x = 1,359,993.14/1,419.90
  6. Step 6: Final answer
    x = 957.81

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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.