Finding the Fourth Proportional to 81.19, 121.58 and 55.20
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Solution
The fourth proportional to 81.19, 121.58 and 55.20 is: 82.66
Step by Step Solution
- Step 1: Write the proportion equation
81.19 : 121.58 = 55.20 : x - Step 2: Convert to fraction form
81.19/121.58 = 55.20/x - Step 3: Cross multiply
81.19x = 121.58 × 55.20 - Step 4: Simplify right side
81.19x = 6,711.22 - Step 5: Solve for x
x = 6,711.22/81.19 - Step 6: Final answer
x = 82.66
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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.