Finding the Fourth Proportional to 128.08, 176.72 and 72.80
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Solution
The fourth proportional to 128.08, 176.72 and 72.80 is: 100.45
Step by Step Solution
- Step 1: Write the proportion equation
128.08 : 176.72 = 72.80 : x - Step 2: Convert to fraction form
128.08/176.72 = 72.80/x - Step 3: Cross multiply
128.08x = 176.72 × 72.80 - Step 4: Simplify right side
128.08x = 12,865.22 - Step 5: Solve for x
x = 12,865.22/128.08 - Step 6: Final answer
x = 100.45
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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.