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Finding the Fourth Proportional to 1,028.95, 1,420.26 and 890.55

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Solution

The fourth proportional to 1,028.95, 1,420.26 and 890.55 is: 1,229.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,028.95 : 1,420.26 = 890.55 : x
  2. Step 2: Convert to fraction form
    1,028.95/1,420.26 = 890.55/x
  3. Step 3: Cross multiply
    1,028.95x = 1,420.26 × 890.55
  4. Step 4: Simplify right side
    1,028.95x = 1,264,808.09
  5. Step 5: Solve for x
    x = 1,264,808.09/1,028.95
  6. Step 6: Final answer
    x = 1,229.23

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.