Finding the Fourth Proportional to 81.21, 121.78 and 27.09
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Solution
The fourth proportional to 81.21, 121.78 and 27.09 is: 40.62
Step by Step Solution
- Step 1: Write the proportion equation
81.21 : 121.78 = 27.09 : x - Step 2: Convert to fraction form
81.21/121.78 = 27.09/x - Step 3: Cross multiply
81.21x = 121.78 × 27.09 - Step 4: Simplify right side
81.21x = 3,299.02 - Step 5: Solve for x
x = 3,299.02/81.21 - Step 6: Final answer
x = 40.62
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Why These Related Problems?
These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.