Home / 1,420.05-2,130.60-639.82

Finding the Fourth Proportional to 1,420.05, 2,130.60 and 639.82

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Solution

The fourth proportional to 1,420.05, 2,130.60 and 639.82 is: 959.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.05 : 2,130.60 = 639.82 : x
  2. Step 2: Convert to fraction form
    1,420.05/2,130.60 = 639.82/x
  3. Step 3: Cross multiply
    1,420.05x = 2,130.60 × 639.82
  4. Step 4: Simplify right side
    1,420.05x = 1,363,193.57
  5. Step 5: Solve for x
    x = 1,363,193.57/1,420.05
  6. Step 6: Final answer
    x = 959.96

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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.