Finding the Fourth Proportional to 121.65, 167.76 and 78
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Solution
The fourth proportional to 121.65, 167.76 and 78 is: 107.56
Step by Step Solution
- Step 1: Write the proportion equation
121.65 : 167.76 = 78 : x - Step 2: Convert to fraction form
121.65/167.76 = 78/x - Step 3: Cross multiply
121.65x = 167.76 × 78 - Step 4: Simplify right side
121.65x = 13,085.28 - Step 5: Solve for x
x = 13,085.28/121.65 - Step 6: Final answer
x = 107.56
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These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.