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Finding the Fourth Proportional to 1,365, 1,883.79 and 840.78

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Solution

The fourth proportional to 1,365, 1,883.79 and 840.78 is: 1,160.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,365 : 1,883.79 = 840.78 : x
  2. Step 2: Convert to fraction form
    1,365/1,883.79 = 840.78/x
  3. Step 3: Cross multiply
    1,365x = 1,883.79 × 840.78
  4. Step 4: Simplify right side
    1,365x = 1,583,852.96
  5. Step 5: Solve for x
    x = 1,583,852.96/1,365
  6. Step 6: Final answer
    x = 1,160.33

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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.