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Finding the Fourth Proportional to 1,368.80, 1,889.09 and 771.31

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Solution

The fourth proportional to 1,368.80, 1,889.09 and 771.31 is: 1,064.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,368.80 : 1,889.09 = 771.31 : x
  2. Step 2: Convert to fraction form
    1,368.80/1,889.09 = 771.31/x
  3. Step 3: Cross multiply
    1,368.80x = 1,889.09 × 771.31
  4. Step 4: Simplify right side
    1,368.80x = 1,457,074.01
  5. Step 5: Solve for x
    x = 1,457,074.01/1,368.80
  6. Step 6: Final answer
    x = 1,064.49

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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.