Finding the Fourth Proportional to 81.18, 121.62 and 76.62
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Solution
The fourth proportional to 81.18, 121.62 and 76.62 is: 114.79
Step by Step Solution
- Step 1: Write the proportion equation
81.18 : 121.62 = 76.62 : x - Step 2: Convert to fraction form
81.18/121.62 = 76.62/x - Step 3: Cross multiply
81.18x = 121.62 × 76.62 - Step 4: Simplify right side
81.18x = 9,318.52 - Step 5: Solve for x
x = 9,318.52/81.18 - Step 6: Final answer
x = 114.79
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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.