Finding the Fourth Proportional to 128.99, 177.97 and 81.74
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Solution
The fourth proportional to 128.99, 177.97 and 81.74 is: 112.78
Step by Step Solution
- Step 1: Write the proportion equation
128.99 : 177.97 = 81.74 : x - Step 2: Convert to fraction form
128.99/177.97 = 81.74/x - Step 3: Cross multiply
128.99x = 177.97 × 81.74 - Step 4: Simplify right side
128.99x = 14,547.01 - Step 5: Solve for x
x = 14,547.01/128.99 - Step 6: Final answer
x = 112.78
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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.