Finding the Fourth Proportional to 128.78, 177.72 and 73.53
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Solution
The fourth proportional to 128.78, 177.72 and 73.53 is: 101.48
Step by Step Solution
- Step 1: Write the proportion equation
128.78 : 177.72 = 73.53 : x - Step 2: Convert to fraction form
128.78/177.72 = 73.53/x - Step 3: Cross multiply
128.78x = 177.72 × 73.53 - Step 4: Simplify right side
128.78x = 13,067.75 - Step 5: Solve for x
x = 13,067.75/128.78 - Step 6: Final answer
x = 101.48
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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.