Finding the Fourth Proportional to 81.60, 121.68 and 74.40
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Solution
The fourth proportional to 81.60, 121.68 and 74.40 is: 110.94
Step by Step Solution
- Step 1: Write the proportion equation
81.60 : 121.68 = 74.40 : x - Step 2: Convert to fraction form
81.60/121.68 = 74.40/x - Step 3: Cross multiply
81.60x = 121.68 × 74.40 - Step 4: Simplify right side
81.60x = 9,052.99 - Step 5: Solve for x
x = 9,052.99/81.60 - Step 6: Final answer
x = 110.94
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Why These Related Problems?
These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.