Finding the Third Proportional to 360 and 420
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Solution
The third proportional to 360 and 420 is: 490
Step by Step Solution
- Step 1: Write the proportion equation
360 : 420 = 420 : x - Step 2: Convert to fraction form
360/420 = 420/x - Step 3: Cross multiply
360x = 420 × 420 - Step 4: Simplify right side
360x = 176,400 - Step 5: Solve for x
x = 176,400/360 - Step 6: Final answer
x = 490
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Why These Related Problems?
These problems maintain the same ratio (1.17) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.