Home / 1,428.20-2,142.30-658.70

Finding the Fourth Proportional to 1,428.20, 2,142.30 and 658.70

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Solution

The fourth proportional to 1,428.20, 2,142.30 and 658.70 is: 988.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,428.20 : 2,142.30 = 658.70 : x
  2. Step 2: Convert to fraction form
    1,428.20/2,142.30 = 658.70/x
  3. Step 3: Cross multiply
    1,428.20x = 2,142.30 × 658.70
  4. Step 4: Simplify right side
    1,428.20x = 1,411,133.01
  5. Step 5: Solve for x
    x = 1,411,133.01/1,428.20
  6. Step 6: Final answer
    x = 988.05

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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.