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Finding the Fourth Proportional to 1,389.75, 1,918.02 and 800.28

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Solution

The fourth proportional to 1,389.75, 1,918.02 and 800.28 is: 1,104.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.75 : 1,918.02 = 800.28 : x
  2. Step 2: Convert to fraction form
    1,389.75/1,918.02 = 800.28/x
  3. Step 3: Cross multiply
    1,389.75x = 1,918.02 × 800.28
  4. Step 4: Simplify right side
    1,389.75x = 1,534,953.05
  5. Step 5: Solve for x
    x = 1,534,953.05/1,389.75
  6. Step 6: Final answer
    x = 1,104.48

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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.