Finding the Fourth Proportional to 128.08, 176.77 and 78.31
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Solution
The fourth proportional to 128.08, 176.77 and 78.31 is: 108.07
Step by Step Solution
- Step 1: Write the proportion equation
128.08 : 176.77 = 78.31 : x - Step 2: Convert to fraction form
128.08/176.77 = 78.31/x - Step 3: Cross multiply
128.08x = 176.77 × 78.31 - Step 4: Simplify right side
128.08x = 13,842.22 - Step 5: Solve for x
x = 13,842.22/128.08 - Step 6: Final answer
x = 108.07
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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.