Home / 1,215.19-1,677.60-861.41

Finding the Fourth Proportional to 1,215.19, 1,677.60 and 861.41

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Solution

The fourth proportional to 1,215.19, 1,677.60 and 861.41 is: 1,189.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,215.19 : 1,677.60 = 861.41 : x
  2. Step 2: Convert to fraction form
    1,215.19/1,677.60 = 861.41/x
  3. Step 3: Cross multiply
    1,215.19x = 1,677.60 × 861.41
  4. Step 4: Simplify right side
    1,215.19x = 1,445,093.03
  5. Step 5: Solve for x
    x = 1,445,093.03/1,215.19
  6. Step 6: Final answer
    x = 1,189.19

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1.5x scale

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.