Home / 1,420.02-2,128.20-639.99

Finding the Fourth Proportional to 1,420.02, 2,128.20 and 639.99

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Solution

The fourth proportional to 1,420.02, 2,128.20 and 639.99 is: 959.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.02 : 2,128.20 = 639.99 : x
  2. Step 2: Convert to fraction form
    1,420.02/2,128.20 = 639.99/x
  3. Step 3: Cross multiply
    1,420.02x = 2,128.20 × 639.99
  4. Step 4: Simplify right side
    1,420.02x = 1,362,026.72
  5. Step 5: Solve for x
    x = 1,362,026.72/1,420.02
  6. Step 6: Final answer
    x = 959.16

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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.