Home / 1,122.12-1,683.21-428.70

Finding the Fourth Proportional to 1,122.12, 1,683.21 and 428.70

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Solution

The fourth proportional to 1,122.12, 1,683.21 and 428.70 is: 643.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,122.12 : 1,683.21 = 428.70 : x
  2. Step 2: Convert to fraction form
    1,122.12/1,683.21 = 428.70/x
  3. Step 3: Cross multiply
    1,122.12x = 1,683.21 × 428.70
  4. Step 4: Simplify right side
    1,122.12x = 721,592.13
  5. Step 5: Solve for x
    x = 721,592.13/1,122.12
  6. Step 6: Final answer
    x = 643.06

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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.