Finding the Fourth Proportional to 81.36, 121.91 and 72.96
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Solution
The fourth proportional to 81.36, 121.91 and 72.96 is: 109.32
Step by Step Solution
- Step 1: Write the proportion equation
81.36 : 121.91 = 72.96 : x - Step 2: Convert to fraction form
81.36/121.91 = 72.96/x - Step 3: Cross multiply
81.36x = 121.91 × 72.96 - Step 4: Simplify right side
81.36x = 8,894.19 - Step 5: Solve for x
x = 8,894.19/81.36 - Step 6: Final answer
x = 109.32
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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.