Finding the Fourth Proportional to 129.20, 193.79 and 81
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Solution
The fourth proportional to 129.20, 193.79 and 81 is: 121.50
Step by Step Solution
- Step 1: Write the proportion equation
129.20 : 193.79 = 81 : x - Step 2: Convert to fraction form
129.20/193.79 = 81/x - Step 3: Cross multiply
129.20x = 193.79 × 81 - Step 4: Simplify right side
129.20x = 15,697.19 - Step 5: Solve for x
x = 15,697.19/129.20 - Step 6: Final answer
x = 121.50
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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.