Finding the Fourth Proportional to 138.10, 207.15 and 128.99
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Solution
The fourth proportional to 138.10, 207.15 and 128.99 is: 193.48
Step by Step Solution
- Step 1: Write the proportion equation
138.10 : 207.15 = 128.99 : x - Step 2: Convert to fraction form
138.10/207.15 = 128.99/x - Step 3: Cross multiply
138.10x = 207.15 × 128.99 - Step 4: Simplify right side
138.10x = 26,719.76 - Step 5: Solve for x
x = 26,719.76/138.10 - Step 6: Final answer
x = 193.48
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Why These Related Problems?
These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.