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Finding the Fourth Proportional to 1,989.78, 2,964.67 and 1,878

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Solution

The fourth proportional to 1,989.78, 2,964.67 and 1,878 is: 2,798.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,989.78 : 2,964.67 = 1,878 : x
  2. Step 2: Convert to fraction form
    1,989.78/2,964.67 = 1,878/x
  3. Step 3: Cross multiply
    1,989.78x = 2,964.67 × 1,878
  4. Step 4: Simplify right side
    1,989.78x = 5,567,650.26
  5. Step 5: Solve for x
    x = 5,567,650.26/1,989.78
  6. Step 6: Final answer
    x = 2,798.12

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.