Finding the Fourth Proportional to 138.15, 206.91 and 91.77
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Solution
The fourth proportional to 138.15, 206.91 and 91.77 is: 137.45
Step by Step Solution
- Step 1: Write the proportion equation
138.15 : 206.91 = 91.77 : x - Step 2: Convert to fraction form
138.15/206.91 = 91.77/x - Step 3: Cross multiply
138.15x = 206.91 × 91.77 - Step 4: Simplify right side
138.15x = 18,988.13 - Step 5: Solve for x
x = 18,988.13/138.15 - Step 6: Final answer
x = 137.45
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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.