Home / 1,188.12-1,640.21-815.25

Finding the Fourth Proportional to 1,188.12, 1,640.21 and 815.25

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Solution

The fourth proportional to 1,188.12, 1,640.21 and 815.25 is: 1,125.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,188.12 : 1,640.21 = 815.25 : x
  2. Step 2: Convert to fraction form
    1,188.12/1,640.21 = 815.25/x
  3. Step 3: Cross multiply
    1,188.12x = 1,640.21 × 815.25
  4. Step 4: Simplify right side
    1,188.12x = 1,337,181.20
  5. Step 5: Solve for x
    x = 1,337,181.20/1,188.12
  6. Step 6: Final answer
    x = 1,125.46

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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.