Finding the Fourth Proportional to 81.71, 122.70 and 81.08
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Solution
The fourth proportional to 81.71, 122.70 and 81.08 is: 121.75
Step by Step Solution
- Step 1: Write the proportion equation
81.71 : 122.70 = 81.08 : x - Step 2: Convert to fraction form
81.71/122.70 = 81.08/x - Step 3: Cross multiply
81.71x = 122.70 × 81.08 - Step 4: Simplify right side
81.71x = 9,948.52 - Step 5: Solve for x
x = 9,948.52/81.71 - Step 6: Final answer
x = 121.75
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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.