Finding the Fourth Proportional to 121.69, 167.83 and 78.09
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Solution
The fourth proportional to 121.69, 167.83 and 78.09 is: 107.70
Step by Step Solution
- Step 1: Write the proportion equation
121.69 : 167.83 = 78.09 : x - Step 2: Convert to fraction form
121.69/167.83 = 78.09/x - Step 3: Cross multiply
121.69x = 167.83 × 78.09 - Step 4: Simplify right side
121.69x = 13,105.84 - Step 5: Solve for x
x = 13,105.84/121.69 - Step 6: Final answer
x = 107.70
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Why These Related Problems?
These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.