Finding the Fourth Proportional to 81.24, 121.68 and 57.12
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Solution
The fourth proportional to 81.24, 121.68 and 57.12 is: 85.55
Step by Step Solution
- Step 1: Write the proportion equation
81.24 : 121.68 = 57.12 : x - Step 2: Convert to fraction form
81.24/121.68 = 57.12/x - Step 3: Cross multiply
81.24x = 121.68 × 57.12 - Step 4: Simplify right side
81.24x = 6,950.36 - Step 5: Solve for x
x = 6,950.36/81.24 - Step 6: Final answer
x = 85.55
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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.