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Finding the Fourth Proportional to 1,989, 2,985.05 and 757.28

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Solution

The fourth proportional to 1,989, 2,985.05 and 757.28 is: 1,136.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,989 : 2,985.05 = 757.28 : x
  2. Step 2: Convert to fraction form
    1,989/2,985.05 = 757.28/x
  3. Step 3: Cross multiply
    1,989x = 2,985.05 × 757.28
  4. Step 4: Simplify right side
    1,989x = 2,260,528.02
  5. Step 5: Solve for x
    x = 2,260,528.02/1,989
  6. Step 6: Final answer
    x = 1,136.51

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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.