Finding the Fourth Proportional to 81.22, 121.65 and 69.09
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Solution
The fourth proportional to 81.22, 121.65 and 69.09 is: 103.48
Step by Step Solution
- Step 1: Write the proportion equation
81.22 : 121.65 = 69.09 : x - Step 2: Convert to fraction form
81.22/121.65 = 69.09/x - Step 3: Cross multiply
81.22x = 121.65 × 69.09 - Step 4: Simplify right side
81.22x = 8,404.80 - Step 5: Solve for x
x = 8,404.80/81.22 - Step 6: Final answer
x = 103.48
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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.