Home / 1,419.40-2,129.10-639.10

Finding the Fourth Proportional to 1,419.40, 2,129.10 and 639.10

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Solution

The fourth proportional to 1,419.40, 2,129.10 and 639.10 is: 958.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,419.40 : 2,129.10 = 639.10 : x
  2. Step 2: Convert to fraction form
    1,419.40/2,129.10 = 639.10/x
  3. Step 3: Cross multiply
    1,419.40x = 2,129.10 × 639.10
  4. Step 4: Simplify right side
    1,419.40x = 1,360,707.81
  5. Step 5: Solve for x
    x = 1,360,707.81/1,419.40
  6. Step 6: Final answer
    x = 958.65

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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.